---
id: CVE-2026-111753
aliases:
  - GHSA-jfgx-762w-99vr
title: >-
  @angular/common: XSRF Token Leakage via URL Parsing Discrepancy in Angular
  HTTP Client (Incomplete fix for CVE-2025-66035)
summary: >-
  @angular/common: XSRF Token Leakage via URL Parsing Discrepancy in Angular
  HTTP Client (Incomplete fix for CVE-2025-66035)
severity: medium
cwe:
  - CWE-201
  - CWE-359
vendor: angular
product: '@angular/common'
ecosystem: npm
affected:
  - '@angular/common >= 21.0.0, < 21.0.3'
  - '@angular/common >= 20.0.0, < 20.3.34'
  - '@angular/common <= 19.2.25'
patched:
  - '@angular/common 21.0.3'
  - '@angular/common 20.3.34'
published: '2026-10-20'
updated: '2026-10-20'
sourceUpdated: '2026-10-20T20:37:58Z'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-jfgx-762w-99vr'
references:
  - url: 'https://github.com/angular/angular/security/advisories/GHSA-jfgx-762w-99vr'
  - url: 'https://github.com/angular/angular/pull/65683'
  - url: 'https://github.com/angular/angular/pull/71295'
  - url: >-
      https://github.com/angular/angular/commit/0659d11c854c9c6b886a2e925afef98d70bb005f
  - url: >-
      https://github.com/angular/angular/commit/20474d3f0fd7c64071add6e84acf720627e5c19b
  - url: >-
      https://github.com/angular/angular/commit/933ce817d53e25926844fa56af8230816763d08e
  - url: 'https://github.com/advisories/GHSA-jfgx-762w-99vr'
tags:
  - ghsa
  - npm
ingestedAt: '2026-10-20T21:19:21.138Z'
---

## Overview

An incomplete fix for [GHSA-58c5-g7wp-6w37](https://github.com/angular/angular/security/advisories/GHSA-58c5-g7wp-6w37) (`CVE-2025-66035`) in `@angular/common`'s HTTP Client (`HttpClient`) allows Cross-Site Request Forgery (XSRF) tokens to be leaked to attacker-controlled cross-origin domains when requests use URLs that exploit parsing discrepancies between regular expressions and the browser's WHATWG URL parser.

### Technical Description

To address `CVE-2025-66035`, `xsrfInterceptorFn` introduced a regular expression (`const ABSOLUTE_URL_REGEX = /^(?:https?:)?\/\//i`) to detect and skip absolute and protocol-relative URLs before attaching the `X-XSRF-TOKEN` header.

However, browsers resolve request URLs passed to `fetch()` and `XMLHttpRequest.open()` using the **WHATWG URL parser**. For `http:` and `https:` schemes, the WHATWG URL standard performs several normalizations prior to resolving the authority/origin:
* Backslashes (`\`) are treated as forward slashes (`/`) — e.g., `/\evil.example/x`, `\\evil.example/x`, `\/evil.example/x`, `https:\\evil.example/x`, `https:/\evil.example/x`.
* Leading and trailing C0 control characters and spaces (`<= 0x20`) are stripped — e.g., `' //evil.example/x'`, `'\0//evil.example/x'`, `'\x1f//evil.example/x'`.
* ASCII tab (`\t`), newline (`\n`), and carriage return (`\r`) characters are removed anywhere in the input — e.g., `'/\t/evil.example/x'`, `'/\n/evil.example/x'`, `'htt\tps://evil.example/x'`.

Because these URLs do not match `/^(?:https?:)?\/\//i`, `xsrfInterceptorFn` treats them as relative same-origin URLs and attaches the `X-XSRF-TOKEN` header, while the browser resolves and dispatches the request to the cross-origin host (`evil.example`).

Note: Angular `21.0.3+` and `22.x` replaced the regular expression with a WHATWG `new URL(req.url, locationOrigin)` origin comparison in [#65683](https://github.com/angular/angular/pull/65683) and were already unaffected. However, the `20.3.x` LTS branch retained the regular expression until `20.3.34`.

### Impact

The token leakage bypasses Angular's built-in XSRF protection on affected versions, allowing an attacker to capture the user's valid `X-XSRF-TOKEN` header if their server permits the request and custom header via CORS. Once obtained, the attacker can perform Cross-Site Request Forgery (CSRF) attacks against the victim user's session.

### Attack Preconditions

1. The victim's Angular application must have **XSRF protection enabled** (enabled by default in `HttpClient`).
2. The attacker must be able to make the application send a state-changing HTTP request (e.g., `POST`, `PUT`, `DELETE`, `PATCH`) to a URL they control (such as `/\attacker.example/api` or ` //attacker.example/api`).

### Patches

The issue is resolved by parsing and comparing the request URL's origin against the application's current origin using the standard `URL` constructor (`new URL(req.url, locationOrigin)`).

* `21.0.3` (and all `22.x` releases)
* `20.3.34`

### Workarounds

If you cannot immediately upgrade to a patched version:
* Validate and normalize outgoing request URLs using `new URL(url, window.location.origin)` and verify that `parsedUrl.origin === window.location.origin` before passing dynamic URLs to mutating `HttpClient` requests.
* Avoid passing untrusted or user-controlled URLs to `HttpClient` mutating methods.

## Affected packages

- `@angular/common >= 21.0.0, < 21.0.3`
- `@angular/common >= 20.0.0, < 20.3.34`
- `@angular/common <= 19.2.25`

## Remediation

Upgrade to a patched release:

- `@angular/common 21.0.3`
- `@angular/common 20.3.34`