From c9da7994a7666c4e3df5e6e6e0dac8b3c4c4f9b3 Mon Sep 17 00:00:00 2001
From: Napalys <napalys@github.com>
Date: Mon, 31 Mar 2025 13:50:56 +0200
Subject: [PATCH 1/4] Added test cases with missing alerts for `Request` and
 `NextRequest`.

---
 .../Request/app/api/proxy/route.serverSide.ts       |  5 +++++
 .../Request/app/api/proxy/route2.serverSide.ts      |  8 ++++++++
 .../Security/CWE-918/Request/package.json           | 13 +++++++++++++
 3 files changed, 26 insertions(+)
 create mode 100644 javascript/ql/test/query-tests/Security/CWE-918/Request/app/api/proxy/route.serverSide.ts
 create mode 100644 javascript/ql/test/query-tests/Security/CWE-918/Request/app/api/proxy/route2.serverSide.ts
 create mode 100644 javascript/ql/test/query-tests/Security/CWE-918/Request/package.json

diff --git a/javascript/ql/test/query-tests/Security/CWE-918/Request/app/api/proxy/route.serverSide.ts b/javascript/ql/test/query-tests/Security/CWE-918/Request/app/api/proxy/route.serverSide.ts
new file mode 100644
index 000000000000..bfee2442afb0
--- /dev/null
+++ b/javascript/ql/test/query-tests/Security/CWE-918/Request/app/api/proxy/route.serverSide.ts
@@ -0,0 +1,5 @@
+export async function POST(req: Request) {
+  const { url } = await req.json(); // $ MISSING: Source[js/request-forgery]
+  const res = await fetch(url); // $ MISSING: Alert[js/request-forgery] Sink[js/request-forgery]
+  return new Response(res.body, { headers: res.headers });
+}
diff --git a/javascript/ql/test/query-tests/Security/CWE-918/Request/app/api/proxy/route2.serverSide.ts b/javascript/ql/test/query-tests/Security/CWE-918/Request/app/api/proxy/route2.serverSide.ts
new file mode 100644
index 000000000000..7b212a73542c
--- /dev/null
+++ b/javascript/ql/test/query-tests/Security/CWE-918/Request/app/api/proxy/route2.serverSide.ts
@@ -0,0 +1,8 @@
+import { NextRequest, NextResponse } from 'next/server';
+
+export async function POST(req: NextRequest) {
+  const { url } = await req.json(); // $ MISSING: Source[js/request-forgery]
+  const res = await fetch(url); // $ MISSING: Alert[js/request-forgery] Sink[js/request-forgery]
+  const data = await res.text();
+  return new NextResponse(data, { headers: res.headers });
+}
diff --git a/javascript/ql/test/query-tests/Security/CWE-918/Request/package.json b/javascript/ql/test/query-tests/Security/CWE-918/Request/package.json
new file mode 100644
index 000000000000..329c7acb8239
--- /dev/null
+++ b/javascript/ql/test/query-tests/Security/CWE-918/Request/package.json
@@ -0,0 +1,13 @@
+{
+  "name": "next-edge-proxy-app",
+  "version": "0.1.0",
+  "private": true,
+  "scripts": {
+    "dev": "next dev",
+    "build": "next build",
+    "start": "next start"
+  },
+  "dependencies": {
+    "next": "15.1.7"
+  }
+}

From 050da9fb8731f29ce0a7fda58bf4def0a8fb43ce Mon Sep 17 00:00:00 2001
From: Napalys <napalys@github.com>
Date: Mon, 31 Mar 2025 13:57:43 +0200
Subject: [PATCH 2/4] Enhance Next.js API endpoint handling for compatibility
 with both Pages and App Router structures.

---
 .../lib/semmle/javascript/frameworks/Next.qll | 58 ++++++++++++++++++-
 .../Request/app/api/proxy/route.serverSide.ts |  4 +-
 .../app/api/proxy/route2.serverSide.ts        |  4 +-
 .../Security/CWE-918/RequestForgery.expected  | 20 +++++++
 4 files changed, 80 insertions(+), 6 deletions(-)

diff --git a/javascript/ql/lib/semmle/javascript/frameworks/Next.qll b/javascript/ql/lib/semmle/javascript/frameworks/Next.qll
index 8fce608a9704..6333c9442d85 100644
--- a/javascript/ql/lib/semmle/javascript/frameworks/Next.qll
+++ b/javascript/ql/lib/semmle/javascript/frameworks/Next.qll
@@ -213,10 +213,12 @@ module NextJS {
   /**
    * Gets a folder that contains API endpoints for a Next.js application.
    * These API endpoints act as Express-like route-handlers.
+   * It matches both the Pages Router (`pages/api/`) Next.js 12 or earlier and
+   * the App Router (`app/api/`) Next.js 13+ structures.
    */
   Folder apiFolder() {
-    result = getANextPackage().getFile().getParentContainer().getFolder("pages").getFolder("api")
-    or
+    result =
+      getANextPackage().getFile().getParentContainer().getFolder(["pages", "app"]).getFolder("api") or
     result = apiFolder().getAFolder()
   }
 
@@ -271,4 +273,56 @@ module NextJS {
       override string getCredentialsKind() { result = "jwt key" }
     }
   }
+
+  /**
+   * A route handler for Next.js 13+ App Router API endpoints, which are defined by exporting
+   * HTTP method functions (like `GET`, `POST`, `PUT`, `DELETE`) from route.js files inside
+   * the `app/api/` directory.
+   */
+  class NextAppRouteHandler extends DataFlow::FunctionNode, Http::Servers::StandardRouteHandler {
+    NextAppRouteHandler() {
+      exists(Module mod | mod.getFile().getParentContainer() = apiFolder() |
+        this = mod.getAnExportedValue(any(Http::RequestMethodName m)).getAFunctionValue() and
+        (
+          this.getParameter(0).hasUnderlyingType("next/server", "NextRequest")
+          or
+          this.getParameter(0).hasUnderlyingType("Request")
+        )
+      )
+    }
+
+    /**
+     * Gets the request parameter, which is either a `NextRequest` object (from `next/server`) or a standard web `Request` object.
+     */
+    DataFlow::SourceNode getRequest() { result = this.getParameter(0) }
+  }
+
+  /**
+   * A source of user-controlled data from a `NextRequest` object (from `next/server`) or a standard web `Request` object
+   * in a Next.js App Router route handler.
+   */
+  class NextAppRequestSource extends Http::RequestInputAccess {
+    NextAppRouteHandler handler;
+    string kind;
+
+    NextAppRequestSource() {
+      (
+        this =
+          handler.getRequest().getAMethodCall(["json", "formData", "blob", "arrayBuffer", "text"])
+        or
+        this = handler.getRequest().getAPropertyRead("body")
+      ) and
+      kind = "body"
+      or
+      this = handler.getRequest().getAPropertyRead(["url", "nextUrl"]) and kind = "url"
+      or
+      this = handler.getRequest().getAPropertyRead("headers") and kind = "headers"
+    }
+
+    override string getKind() { result = kind }
+
+    override Http::RouteHandler getRouteHandler() { result = handler }
+
+    override string getSourceType() { result = "Next.js App Router request" }
+  }
 }
diff --git a/javascript/ql/test/query-tests/Security/CWE-918/Request/app/api/proxy/route.serverSide.ts b/javascript/ql/test/query-tests/Security/CWE-918/Request/app/api/proxy/route.serverSide.ts
index bfee2442afb0..f3d05b7e5aa2 100644
--- a/javascript/ql/test/query-tests/Security/CWE-918/Request/app/api/proxy/route.serverSide.ts
+++ b/javascript/ql/test/query-tests/Security/CWE-918/Request/app/api/proxy/route.serverSide.ts
@@ -1,5 +1,5 @@
 export async function POST(req: Request) {
-  const { url } = await req.json(); // $ MISSING: Source[js/request-forgery]
-  const res = await fetch(url); // $ MISSING: Alert[js/request-forgery] Sink[js/request-forgery]
+  const { url } = await req.json(); // $ Source[js/request-forgery]
+  const res = await fetch(url); // $ Alert[js/request-forgery] Sink[js/request-forgery]
   return new Response(res.body, { headers: res.headers });
 }
diff --git a/javascript/ql/test/query-tests/Security/CWE-918/Request/app/api/proxy/route2.serverSide.ts b/javascript/ql/test/query-tests/Security/CWE-918/Request/app/api/proxy/route2.serverSide.ts
index 7b212a73542c..051ba67e401f 100644
--- a/javascript/ql/test/query-tests/Security/CWE-918/Request/app/api/proxy/route2.serverSide.ts
+++ b/javascript/ql/test/query-tests/Security/CWE-918/Request/app/api/proxy/route2.serverSide.ts
@@ -1,8 +1,8 @@
 import { NextRequest, NextResponse } from 'next/server';
 
 export async function POST(req: NextRequest) {
-  const { url } = await req.json(); // $ MISSING: Source[js/request-forgery]
-  const res = await fetch(url); // $ MISSING: Alert[js/request-forgery] Sink[js/request-forgery]
+  const { url } = await req.json(); // $ Source[js/request-forgery]
+  const res = await fetch(url); // $ Alert[js/request-forgery] Sink[js/request-forgery]
   const data = await res.text();
   return new NextResponse(data, { headers: res.headers });
 }
diff --git a/javascript/ql/test/query-tests/Security/CWE-918/RequestForgery.expected b/javascript/ql/test/query-tests/Security/CWE-918/RequestForgery.expected
index 78b02c5f7db4..b8436fa6722e 100644
--- a/javascript/ql/test/query-tests/Security/CWE-918/RequestForgery.expected
+++ b/javascript/ql/test/query-tests/Security/CWE-918/RequestForgery.expected
@@ -1,4 +1,6 @@
 #select
+| Request/app/api/proxy/route2.serverSide.ts:5:21:5:30 | fetch(url) | Request/app/api/proxy/route2.serverSide.ts:4:25:4:34 | req.json() | Request/app/api/proxy/route2.serverSide.ts:5:27:5:29 | url | The $@ of this request depends on a $@. | Request/app/api/proxy/route2.serverSide.ts:5:27:5:29 | url | URL | Request/app/api/proxy/route2.serverSide.ts:4:25:4:34 | req.json() | user-provided value |
+| Request/app/api/proxy/route.serverSide.ts:3:21:3:30 | fetch(url) | Request/app/api/proxy/route.serverSide.ts:2:25:2:34 | req.json() | Request/app/api/proxy/route.serverSide.ts:3:27:3:29 | url | The $@ of this request depends on a $@. | Request/app/api/proxy/route.serverSide.ts:3:27:3:29 | url | URL | Request/app/api/proxy/route.serverSide.ts:2:25:2:34 | req.json() | user-provided value |
 | apollo.serverSide.ts:8:39:8:64 | get(fil ...  => {}) | apollo.serverSide.ts:7:36:7:44 | { files } | apollo.serverSide.ts:8:43:8:50 | file.url | The $@ of this request depends on a $@. | apollo.serverSide.ts:8:43:8:50 | file.url | URL | apollo.serverSide.ts:7:36:7:44 | { files } | user-provided value |
 | apollo.serverSide.ts:18:37:18:62 | get(fil ...  => {}) | apollo.serverSide.ts:17:34:17:42 | { files } | apollo.serverSide.ts:18:41:18:48 | file.url | The $@ of this request depends on a $@. | apollo.serverSide.ts:18:41:18:48 | file.url | URL | apollo.serverSide.ts:17:34:17:42 | { files } | user-provided value |
 | axiosInterceptors.serverSide.js:11:26:11:40 | userProvidedUrl | axiosInterceptors.serverSide.js:19:21:19:28 | req.body | axiosInterceptors.serverSide.js:11:26:11:40 | userProvidedUrl | The $@ of this request depends on a $@. | axiosInterceptors.serverSide.js:11:26:11:40 | userProvidedUrl | endpoint | axiosInterceptors.serverSide.js:19:21:19:28 | req.body | user-provided value |
@@ -27,6 +29,14 @@
 | serverSide.js:125:5:128:6 | axios({ ... \\n    }) | serverSide.js:123:29:123:35 | req.url | serverSide.js:127:14:127:20 | tainted | The $@ of this request depends on a $@. | serverSide.js:127:14:127:20 | tainted | URL | serverSide.js:123:29:123:35 | req.url | user-provided value |
 | serverSide.js:131:5:131:20 | axios.get(myUrl) | serverSide.js:123:29:123:35 | req.url | serverSide.js:131:15:131:19 | myUrl | The $@ of this request depends on a $@. | serverSide.js:131:15:131:19 | myUrl | URL | serverSide.js:123:29:123:35 | req.url | user-provided value |
 edges
+| Request/app/api/proxy/route2.serverSide.ts:4:9:4:15 | { url } | Request/app/api/proxy/route2.serverSide.ts:4:9:4:34 | url | provenance |  |
+| Request/app/api/proxy/route2.serverSide.ts:4:9:4:34 | url | Request/app/api/proxy/route2.serverSide.ts:5:27:5:29 | url | provenance |  |
+| Request/app/api/proxy/route2.serverSide.ts:4:19:4:34 | await req.json() | Request/app/api/proxy/route2.serverSide.ts:4:9:4:15 | { url } | provenance |  |
+| Request/app/api/proxy/route2.serverSide.ts:4:25:4:34 | req.json() | Request/app/api/proxy/route2.serverSide.ts:4:19:4:34 | await req.json() | provenance |  |
+| Request/app/api/proxy/route.serverSide.ts:2:9:2:15 | { url } | Request/app/api/proxy/route.serverSide.ts:2:9:2:34 | url | provenance |  |
+| Request/app/api/proxy/route.serverSide.ts:2:9:2:34 | url | Request/app/api/proxy/route.serverSide.ts:3:27:3:29 | url | provenance |  |
+| Request/app/api/proxy/route.serverSide.ts:2:19:2:34 | await req.json() | Request/app/api/proxy/route.serverSide.ts:2:9:2:15 | { url } | provenance |  |
+| Request/app/api/proxy/route.serverSide.ts:2:25:2:34 | req.json() | Request/app/api/proxy/route.serverSide.ts:2:19:2:34 | await req.json() | provenance |  |
 | apollo.serverSide.ts:7:36:7:44 | files | apollo.serverSide.ts:8:13:8:17 | files | provenance |  |
 | apollo.serverSide.ts:7:36:7:44 | { files } | apollo.serverSide.ts:7:36:7:44 | files | provenance |  |
 | apollo.serverSide.ts:8:13:8:17 | files | apollo.serverSide.ts:8:28:8:31 | file | provenance |  |
@@ -91,6 +101,16 @@ edges
 | serverSide.js:130:9:130:45 | myUrl | serverSide.js:131:15:131:19 | myUrl | provenance |  |
 | serverSide.js:130:37:130:43 | tainted | serverSide.js:130:9:130:45 | myUrl | provenance |  |
 nodes
+| Request/app/api/proxy/route2.serverSide.ts:4:9:4:15 | { url } | semmle.label | { url } |
+| Request/app/api/proxy/route2.serverSide.ts:4:9:4:34 | url | semmle.label | url |
+| Request/app/api/proxy/route2.serverSide.ts:4:19:4:34 | await req.json() | semmle.label | await req.json() |
+| Request/app/api/proxy/route2.serverSide.ts:4:25:4:34 | req.json() | semmle.label | req.json() |
+| Request/app/api/proxy/route2.serverSide.ts:5:27:5:29 | url | semmle.label | url |
+| Request/app/api/proxy/route.serverSide.ts:2:9:2:15 | { url } | semmle.label | { url } |
+| Request/app/api/proxy/route.serverSide.ts:2:9:2:34 | url | semmle.label | url |
+| Request/app/api/proxy/route.serverSide.ts:2:19:2:34 | await req.json() | semmle.label | await req.json() |
+| Request/app/api/proxy/route.serverSide.ts:2:25:2:34 | req.json() | semmle.label | req.json() |
+| Request/app/api/proxy/route.serverSide.ts:3:27:3:29 | url | semmle.label | url |
 | apollo.serverSide.ts:7:36:7:44 | files | semmle.label | files |
 | apollo.serverSide.ts:7:36:7:44 | { files } | semmle.label | { files } |
 | apollo.serverSide.ts:8:13:8:17 | files | semmle.label | files |

From d7691eaedd5259f008138af0b1d9cf3cbce1a38e Mon Sep 17 00:00:00 2001
From: Napalys <napalys@github.com>
Date: Tue, 1 Apr 2025 14:14:27 +0200
Subject: [PATCH 3/4] Added test cases for `NextResponse` and `Response`

---
 .../CWE-079/ReflectedXss/app/api/route.ts     | 30 +++++++++++++++++++
 .../ReflectedXss/app/api/routeNextRequest.ts  |  7 +++++
 2 files changed, 37 insertions(+)
 create mode 100644 javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/app/api/route.ts
 create mode 100644 javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/app/api/routeNextRequest.ts

diff --git a/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/app/api/route.ts b/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/app/api/route.ts
new file mode 100644
index 000000000000..a863c8c191ca
--- /dev/null
+++ b/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/app/api/route.ts
@@ -0,0 +1,30 @@
+export async function POST(req: Request) {
+    const body = await req.json(); // $ MISSING: Source
+
+    new Response(body, {headers: { 'Content-Type': 'application/json' }}); // This is okay, since content type is set to application/json
+    new Response(body, {headers: { 'Content-Type': 'text/html' }});  // $ MISSING: Alert
+    
+    const headers2 = new Headers(req.headers);
+    headers2.append('Content-Type', 'application/json');
+    new Response(body, { headers: headers2 }); // This is okay, since content type is set to application/json
+
+    const headers3 = new Headers(req.headers);
+    headers3.append('Content-Type', 'text/html');
+    new Response(body, { headers: headers3 }); // $ MISSING: Alert
+
+    const headers4 = new Headers({
+        ...Object.fromEntries(req.headers),
+        'Content-Type': 'application/json'
+    });
+    new Response(body, { headers: headers4 }); // This is okay, since content type is set to application/json
+
+    const headers5 = new Headers({
+        ...Object.fromEntries(req.headers),
+        'Content-Type': 'text/html'
+    });
+    new Response(body, { headers: headers5 }); // $ MISSING: Alert
+
+    const headers = new Headers(req.headers);
+    headers.set('Content-Type', 'text/html');
+    return new Response(body, { headers }); // $ MISSING: Alert
+}
diff --git a/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/app/api/routeNextRequest.ts b/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/app/api/routeNextRequest.ts
new file mode 100644
index 000000000000..65a1b57488c6
--- /dev/null
+++ b/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/app/api/routeNextRequest.ts
@@ -0,0 +1,7 @@
+import { NextRequest, NextResponse } from 'next/server';
+
+export async function POST(req: NextRequest) {
+  const data = await req.json(); // $ MISSING: Source
+  new NextResponse(data, {headers: { 'Content-Type': 'text/html' }});  // $ MISSING: Alert
+  return new NextResponse(data, { headers: req.headers });  // $ MISSING: Alert
+}

From ca5a834a2356ecd161243b0bfa68423ae66d63da Mon Sep 17 00:00:00 2001
From: Napalys <napalys@github.com>
Date: Tue, 1 Apr 2025 14:44:27 +0200
Subject: [PATCH 4/4] Modeled `Response` and `NextResponse` as potential sinks.

---
 .../lib/semmle/javascript/frameworks/Next.qll | 41 +++++++++++++++++++
 .../dataflow/ReflectedXssCustomizations.qll   | 35 ++++++++++++++++
 .../ReflectedXss/ReflectedXss.expected        | 28 +++++++++++++
 .../ReflectedXssWithCustomSanitizer.expected  |  6 +++
 .../CWE-079/ReflectedXss/app/api/route.ts     | 10 ++---
 .../ReflectedXss/app/api/routeNextRequest.ts  |  6 +--
 6 files changed, 118 insertions(+), 8 deletions(-)

diff --git a/javascript/ql/lib/semmle/javascript/frameworks/Next.qll b/javascript/ql/lib/semmle/javascript/frameworks/Next.qll
index 6333c9442d85..0ce1f3d6c068 100644
--- a/javascript/ql/lib/semmle/javascript/frameworks/Next.qll
+++ b/javascript/ql/lib/semmle/javascript/frameworks/Next.qll
@@ -3,6 +3,7 @@
  */
 
 import javascript
+import semmle.javascript.security.dataflow.ReflectedXssCustomizations
 
 /**
  * Provides classes and predicates modeling [Next.js](https://www.npmjs.com/package/next).
@@ -325,4 +326,44 @@ module NextJS {
 
     override string getSourceType() { result = "Next.js App Router request" }
   }
+
+  /**
+   * Gets the headers value from the options object passed to a Next.js Response constructor.
+   */
+  DataFlow::Node getContentTypeHeadersForResponse(DataFlow::InvokeNode responseNode) {
+    exists(DataFlow::ObjectLiteralNode options |
+      options.flowsTo(responseNode.getArgument(1)) and
+      result = options.getAPropertyWrite("headers").getRhs()
+    )
+  }
+
+  /**
+   * A sink representing response content in Next.js API routes that may be vulnerable
+   * to XSS attacks.
+   *
+   * This class identifies responses created with the standard `Response` constructor
+   * or Next.js `NextResponse`.
+   */
+  class WebApiResponseSink extends Http::ResponseSendArgument {
+    WebApiResponseSink() {
+      exists(
+        DataFlow::InvokeNode response, DataFlow::ObjectLiteralNode options, DataFlow::Node headers
+      |
+        response =
+          [
+            DataFlow::globalVarRef("Response").getAnInstantiation(),
+            API::moduleImport("next/server").getMember("NextResponse").getAnInstantiation()
+          ] and
+        this = response.getArgument(0) and
+        options.flowsTo(response.getArgument(1)) and
+        headers = getContentTypeHeadersForResponse(response) and
+        not exists(DataFlow::Node goodHeaders |
+          goodHeaders = ReflectedXss::getGoodContentHeaders() and
+          goodHeaders.getALocalSource().flowsTo(headers)
+        )
+      )
+    }
+
+    override Http::RouteHandler getRouteHandler() { none() }
+  }
 }
diff --git a/javascript/ql/lib/semmle/javascript/security/dataflow/ReflectedXssCustomizations.qll b/javascript/ql/lib/semmle/javascript/security/dataflow/ReflectedXssCustomizations.qll
index 6ddedd4f727b..249b185343e4 100644
--- a/javascript/ql/lib/semmle/javascript/security/dataflow/ReflectedXssCustomizations.qll
+++ b/javascript/ql/lib/semmle/javascript/security/dataflow/ReflectedXssCustomizations.qll
@@ -136,6 +136,41 @@ module ReflectedXss {
     }
   }
 
+  /**
+   * Gets a data flow node representing headers that set content-type to a value
+   * that is not susceptible to XSS attacks.
+   */
+  DataFlow::Node getGoodContentHeaders() {
+    // Case 1: Direct object literal with content-type `headers: { 'Content-Type': 'goodType' }`
+    exists(DataFlow::ObjectLiteralNode headersObj, string name, string contentType |
+      result = headersObj and
+      name.toLowerCase() = "content-type" and
+      headersObj.getAPropertyWrite(name).getRhs().mayHaveStringValue(contentType) and
+      not contentType.toLowerCase().matches(xssUnsafeContentType() + "%")
+    )
+    or
+    // Case 2: Headers with set/append methods `headers.append('Content-Type', 'goodType')`
+    exists(DataFlow::MethodCallNode call, string contentType |
+      call.getMethodName() = ["set", "append"] and
+      call.getReceiver().getALocalSource() = result and
+      call.getArgument(0).mayHaveStringValue(any(string s | s.toLowerCase() = "content-type")) and
+      call.getArgument(1).mayHaveStringValue(contentType) and
+      not contentType.toLowerCase().matches(xssUnsafeContentType() + "%")
+    )
+    or
+    // Case 3: New Headers with initial content-type `new Headers({ 'Content-Type': 'goodType' })`
+    exists(
+      NewExpr headersNew, DataFlow::ObjectLiteralNode headersInit, string name, string contentType
+    |
+      result.asExpr() = headersNew and
+      headersNew.getCalleeName() = "Headers" and
+      headersInit.flowsTo(DataFlow::valueNode(headersNew.getArgument(0))) and
+      name.toLowerCase() = "content-type" and
+      headersInit.getAPropertyWrite(name).getRhs().mayHaveStringValue(contentType) and
+      not contentType.toLowerCase().matches(xssUnsafeContentType() + "%")
+    )
+  }
+
   private class SinkFromModel extends Sink {
     SinkFromModel() { this = ModelOutput::getASinkNode("html-injection").asSink() }
   }
diff --git a/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/ReflectedXss.expected b/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/ReflectedXss.expected
index d85a90e4026a..81228aab07cd 100644
--- a/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/ReflectedXss.expected
+++ b/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/ReflectedXss.expected
@@ -27,6 +27,12 @@
 | ReflectedXssContentTypes.js:39:13:39:35 | "FOO: " ... rams.id | ReflectedXssContentTypes.js:39:23:39:35 | req.params.id | ReflectedXssContentTypes.js:39:13:39:35 | "FOO: " ... rams.id | Cross-site scripting vulnerability due to a $@. | ReflectedXssContentTypes.js:39:23:39:35 | req.params.id | user-provided value |
 | ReflectedXssContentTypes.js:70:12:70:34 | "FOO: " ... rams.id | ReflectedXssContentTypes.js:70:22:70:34 | req.params.id | ReflectedXssContentTypes.js:70:12:70:34 | "FOO: " ... rams.id | Cross-site scripting vulnerability due to a $@. | ReflectedXssContentTypes.js:70:22:70:34 | req.params.id | user-provided value |
 | ReflectedXssGood3.js:139:12:139:27 | escapeHtml3(url) | ReflectedXssGood3.js:135:15:135:27 | req.params.id | ReflectedXssGood3.js:139:12:139:27 | escapeHtml3(url) | Cross-site scripting vulnerability due to a $@. | ReflectedXssGood3.js:135:15:135:27 | req.params.id | user-provided value |
+| app/api/route.ts:5:18:5:21 | body | app/api/route.ts:2:24:2:33 | req.json() | app/api/route.ts:5:18:5:21 | body | Cross-site scripting vulnerability due to a $@. | app/api/route.ts:2:24:2:33 | req.json() | user-provided value |
+| app/api/route.ts:13:18:13:21 | body | app/api/route.ts:2:24:2:33 | req.json() | app/api/route.ts:13:18:13:21 | body | Cross-site scripting vulnerability due to a $@. | app/api/route.ts:2:24:2:33 | req.json() | user-provided value |
+| app/api/route.ts:25:18:25:21 | body | app/api/route.ts:2:24:2:33 | req.json() | app/api/route.ts:25:18:25:21 | body | Cross-site scripting vulnerability due to a $@. | app/api/route.ts:2:24:2:33 | req.json() | user-provided value |
+| app/api/route.ts:29:25:29:28 | body | app/api/route.ts:2:24:2:33 | req.json() | app/api/route.ts:29:25:29:28 | body | Cross-site scripting vulnerability due to a $@. | app/api/route.ts:2:24:2:33 | req.json() | user-provided value |
+| app/api/routeNextRequest.ts:5:20:5:23 | data | app/api/routeNextRequest.ts:4:22:4:31 | req.json() | app/api/routeNextRequest.ts:5:20:5:23 | data | Cross-site scripting vulnerability due to a $@. | app/api/routeNextRequest.ts:4:22:4:31 | req.json() | user-provided value |
+| app/api/routeNextRequest.ts:6:27:6:30 | data | app/api/routeNextRequest.ts:4:22:4:31 | req.json() | app/api/routeNextRequest.ts:6:27:6:30 | data | Cross-site scripting vulnerability due to a $@. | app/api/routeNextRequest.ts:4:22:4:31 | req.json() | user-provided value |
 | etherpad.js:11:12:11:19 | response | etherpad.js:9:16:9:30 | req.query.jsonp | etherpad.js:11:12:11:19 | response | Cross-site scripting vulnerability due to a $@. | etherpad.js:9:16:9:30 | req.query.jsonp | user-provided value |
 | formatting.js:6:14:6:47 | util.fo ... , evil) | formatting.js:4:16:4:29 | req.query.evil | formatting.js:6:14:6:47 | util.fo ... , evil) | Cross-site scripting vulnerability due to a $@. | formatting.js:4:16:4:29 | req.query.evil | user-provided value |
 | formatting.js:7:14:7:53 | require ... , evil) | formatting.js:4:16:4:29 | req.query.evil | formatting.js:7:14:7:53 | require ... , evil) | Cross-site scripting vulnerability due to a $@. | formatting.js:4:16:4:29 | req.query.evil | user-provided value |
@@ -119,6 +125,16 @@ edges
 | ReflectedXssGood3.js:135:15:135:27 | req.params.id | ReflectedXssGood3.js:135:9:135:27 | url | provenance |  |
 | ReflectedXssGood3.js:139:24:139:26 | url | ReflectedXssGood3.js:68:22:68:26 | value | provenance |  |
 | ReflectedXssGood3.js:139:24:139:26 | url | ReflectedXssGood3.js:139:12:139:27 | escapeHtml3(url) | provenance |  |
+| app/api/route.ts:2:11:2:33 | body | app/api/route.ts:5:18:5:21 | body | provenance |  |
+| app/api/route.ts:2:11:2:33 | body | app/api/route.ts:13:18:13:21 | body | provenance |  |
+| app/api/route.ts:2:11:2:33 | body | app/api/route.ts:25:18:25:21 | body | provenance |  |
+| app/api/route.ts:2:11:2:33 | body | app/api/route.ts:29:25:29:28 | body | provenance |  |
+| app/api/route.ts:2:18:2:33 | await req.json() | app/api/route.ts:2:11:2:33 | body | provenance |  |
+| app/api/route.ts:2:24:2:33 | req.json() | app/api/route.ts:2:18:2:33 | await req.json() | provenance |  |
+| app/api/routeNextRequest.ts:4:9:4:31 | data | app/api/routeNextRequest.ts:5:20:5:23 | data | provenance |  |
+| app/api/routeNextRequest.ts:4:9:4:31 | data | app/api/routeNextRequest.ts:6:27:6:30 | data | provenance |  |
+| app/api/routeNextRequest.ts:4:16:4:31 | await req.json() | app/api/routeNextRequest.ts:4:9:4:31 | data | provenance |  |
+| app/api/routeNextRequest.ts:4:22:4:31 | req.json() | app/api/routeNextRequest.ts:4:16:4:31 | await req.json() | provenance |  |
 | etherpad.js:9:5:9:53 | response | etherpad.js:11:12:11:19 | response | provenance |  |
 | etherpad.js:9:16:9:30 | req.query.jsonp | etherpad.js:9:5:9:53 | response | provenance |  |
 | formatting.js:4:9:4:29 | evil | formatting.js:6:43:6:46 | evil | provenance |  |
@@ -290,6 +306,18 @@ nodes
 | ReflectedXssGood3.js:135:15:135:27 | req.params.id | semmle.label | req.params.id |
 | ReflectedXssGood3.js:139:12:139:27 | escapeHtml3(url) | semmle.label | escapeHtml3(url) |
 | ReflectedXssGood3.js:139:24:139:26 | url | semmle.label | url |
+| app/api/route.ts:2:11:2:33 | body | semmle.label | body |
+| app/api/route.ts:2:18:2:33 | await req.json() | semmle.label | await req.json() |
+| app/api/route.ts:2:24:2:33 | req.json() | semmle.label | req.json() |
+| app/api/route.ts:5:18:5:21 | body | semmle.label | body |
+| app/api/route.ts:13:18:13:21 | body | semmle.label | body |
+| app/api/route.ts:25:18:25:21 | body | semmle.label | body |
+| app/api/route.ts:29:25:29:28 | body | semmle.label | body |
+| app/api/routeNextRequest.ts:4:9:4:31 | data | semmle.label | data |
+| app/api/routeNextRequest.ts:4:16:4:31 | await req.json() | semmle.label | await req.json() |
+| app/api/routeNextRequest.ts:4:22:4:31 | req.json() | semmle.label | req.json() |
+| app/api/routeNextRequest.ts:5:20:5:23 | data | semmle.label | data |
+| app/api/routeNextRequest.ts:6:27:6:30 | data | semmle.label | data |
 | etherpad.js:9:5:9:53 | response | semmle.label | response |
 | etherpad.js:9:16:9:30 | req.query.jsonp | semmle.label | req.query.jsonp |
 | etherpad.js:11:12:11:19 | response | semmle.label | response |
diff --git a/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/ReflectedXssWithCustomSanitizer.expected b/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/ReflectedXssWithCustomSanitizer.expected
index fb0748b3acdd..b44a1d0ea492 100644
--- a/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/ReflectedXssWithCustomSanitizer.expected
+++ b/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/ReflectedXssWithCustomSanitizer.expected
@@ -26,6 +26,12 @@
 | ReflectedXssContentTypes.js:39:13:39:35 | "FOO: " ... rams.id | Cross-site scripting vulnerability due to $@. | ReflectedXssContentTypes.js:39:23:39:35 | req.params.id | user-provided value |
 | ReflectedXssContentTypes.js:70:12:70:34 | "FOO: " ... rams.id | Cross-site scripting vulnerability due to $@. | ReflectedXssContentTypes.js:70:22:70:34 | req.params.id | user-provided value |
 | ReflectedXssGood3.js:139:12:139:27 | escapeHtml3(url) | Cross-site scripting vulnerability due to $@. | ReflectedXssGood3.js:135:15:135:27 | req.params.id | user-provided value |
+| app/api/route.ts:5:18:5:21 | body | Cross-site scripting vulnerability due to $@. | app/api/route.ts:2:24:2:33 | req.json() | user-provided value |
+| app/api/route.ts:13:18:13:21 | body | Cross-site scripting vulnerability due to $@. | app/api/route.ts:2:24:2:33 | req.json() | user-provided value |
+| app/api/route.ts:25:18:25:21 | body | Cross-site scripting vulnerability due to $@. | app/api/route.ts:2:24:2:33 | req.json() | user-provided value |
+| app/api/route.ts:29:25:29:28 | body | Cross-site scripting vulnerability due to $@. | app/api/route.ts:2:24:2:33 | req.json() | user-provided value |
+| app/api/routeNextRequest.ts:5:20:5:23 | data | Cross-site scripting vulnerability due to $@. | app/api/routeNextRequest.ts:4:22:4:31 | req.json() | user-provided value |
+| app/api/routeNextRequest.ts:6:27:6:30 | data | Cross-site scripting vulnerability due to $@. | app/api/routeNextRequest.ts:4:22:4:31 | req.json() | user-provided value |
 | formatting.js:6:14:6:47 | util.fo ... , evil) | Cross-site scripting vulnerability due to $@. | formatting.js:4:16:4:29 | req.query.evil | user-provided value |
 | formatting.js:7:14:7:53 | require ... , evil) | Cross-site scripting vulnerability due to $@. | formatting.js:4:16:4:29 | req.query.evil | user-provided value |
 | live-server.js:6:13:6:50 | `<html> ... /html>` | Cross-site scripting vulnerability due to $@. | live-server.js:4:21:4:27 | req.url | user-provided value |
diff --git a/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/app/api/route.ts b/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/app/api/route.ts
index a863c8c191ca..755f1421308a 100644
--- a/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/app/api/route.ts
+++ b/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/app/api/route.ts
@@ -1,8 +1,8 @@
 export async function POST(req: Request) {
-    const body = await req.json(); // $ MISSING: Source
+    const body = await req.json(); // $ Source
 
     new Response(body, {headers: { 'Content-Type': 'application/json' }}); // This is okay, since content type is set to application/json
-    new Response(body, {headers: { 'Content-Type': 'text/html' }});  // $ MISSING: Alert
+    new Response(body, {headers: { 'Content-Type': 'text/html' }});  // $ Alert
     
     const headers2 = new Headers(req.headers);
     headers2.append('Content-Type', 'application/json');
@@ -10,7 +10,7 @@ export async function POST(req: Request) {
 
     const headers3 = new Headers(req.headers);
     headers3.append('Content-Type', 'text/html');
-    new Response(body, { headers: headers3 }); // $ MISSING: Alert
+    new Response(body, { headers: headers3 }); // $ Alert
 
     const headers4 = new Headers({
         ...Object.fromEntries(req.headers),
@@ -22,9 +22,9 @@ export async function POST(req: Request) {
         ...Object.fromEntries(req.headers),
         'Content-Type': 'text/html'
     });
-    new Response(body, { headers: headers5 }); // $ MISSING: Alert
+    new Response(body, { headers: headers5 }); // $ Alert
 
     const headers = new Headers(req.headers);
     headers.set('Content-Type', 'text/html');
-    return new Response(body, { headers }); // $ MISSING: Alert
+    return new Response(body, { headers }); // $ Alert
 }
diff --git a/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/app/api/routeNextRequest.ts b/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/app/api/routeNextRequest.ts
index 65a1b57488c6..d495a5aae523 100644
--- a/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/app/api/routeNextRequest.ts
+++ b/javascript/ql/test/query-tests/Security/CWE-079/ReflectedXss/app/api/routeNextRequest.ts
@@ -1,7 +1,7 @@
 import { NextRequest, NextResponse } from 'next/server';
 
 export async function POST(req: NextRequest) {
-  const data = await req.json(); // $ MISSING: Source
-  new NextResponse(data, {headers: { 'Content-Type': 'text/html' }});  // $ MISSING: Alert
-  return new NextResponse(data, { headers: req.headers });  // $ MISSING: Alert
+  const data = await req.json(); // $ Source
+  new NextResponse(data, {headers: { 'Content-Type': 'text/html' }});  // $ Alert
+  return new NextResponse(data, { headers: req.headers });  // $ Alert
 }