CVE-2026-111753 Angular: XSRF Token Leakage via URL Parsing Discrepancy in Angular HTTP Client (Incomplete fix for CVE-2025-66035)

Description

Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 20.3.34 and 21.0.3, the @angular/common HttpClient function xsrfInterceptorFn uses a regular expression that does not normalize request URLs in the same way as the browser's WHATWG URL parser. With XSRF protection enabled, a mutating HTTP request to an attacker-controlled URL containing backslashes, stripped control characters or spaces, or removable ASCII whitespace can be misclassified as relative and same-origin, causing the interceptor to attach the X-XSRF-TOKEN header before the browser dispatches the request to a cross-origin host. With permissive CORS handling for the custom header, the attacker can obtain the victim's XSRF token and use it to perform cross-site request forgery against the victim session. This issue is fixed in versions 20.3.34 and 21.0.3.

Exploitable remotely over the network, without an account and if a user takes an action; an attacker can seriously compromise confidentiality, integrity or availability.

Attack vector

Network

Attack complexity

Low

Attack requirements

Present

Privileges required

None

Interaction

Active

Confidentiality

High

Integrity

None

Availability

None

Confidentiality of other systems

None

Integrity of other systems

None

Availability of other systems

None

Affected products and versions