Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 22.0.1, 21.2.17, and 20.3.25, an issue in the @angular/compiler package allows bypassing DOM property sanitization through the use of two-way property bindings. Specifically, when a native DOM property that requires sanitization (such as innerHTML, srcdoc, src, href, data, or sandbox) is bound using the two-way binding syntax (e.g., [(innerHTML)]="value" or bindon-innerHTML="value"), the Angular template compiler failed to apply the appropriate schema-derived sanitizer resolution to the TwoWayProperty operation. As a result, native two-way DOM bindings were emitted without the required sanitizer function, whereas equivalent one-way bindings would be properly sanitized. This flaw enables an attacker who can control the value of a two-way bound sensitive property to bypass Angular's built-in sanitization logic, potentially leading to client-side Cross-Site Scripting (XSS). This vulnerability is fixed in 22.0.1, 21.2.17, and 20.3.25.

Affected: npm: @angular/compiler

An issue in the `@angular/compiler` package allows bypassing DOM property sanitization through the use of two-way property bindings.

Specifically, when a native DOM property that requires sanitization (such as `innerHTML`, `srcdoc`, `src`, `href`, `data`, or `sandbox`) is bound using the two-way binding syntax (e.g., `[(innerHTML)]="value"` or `bindon-innerHTML="value"`), the Angular template compiler failed to apply the appropriate schema-derived sanitizer resolution to the `TwoWayProperty` operation. As a result, native two-way DOM bindings were emitted without the required sanitizer function, whereas equivalent one-way bindings would be properly sanitized.

This flaw enables an attacker who can control the value of a two-way bound sensitive property to bypass Angular's built-in sanitization logic, potentially leading to client-side Cross-Site Scripting (XSS).

### Impact Any Angular application that uses two-way data binding (`[()]` or `bindon-`) on security-sensitive native DOM properties (like `innerHTML`, `href` on `<a>`, `src` on `<img>`/`<iframe>`, etc.) is vulnerable to this security bypass.

Once exploited, this allows a malicious actor to supply an unsanitized property binding value that bypasses core sanitization constraints. This could lead to the execution of arbitrary JavaScript within the target user's browser context, potentially resulting in session hijacking, sensitive data exposure, or unauthorized actions on behalf of the user.

### Attack Preconditions…

Affected: Ubuntu:Pro:16.04:LTS: angular.js, Ubuntu:Pro:18.04:LTS: angular.js, Ubuntu:Pro:20.04:LTS: angular.js, Ubuntu:22.04:LTS: angular.js, Ubuntu:24.04:LTS: angular.js, Ubuntu:25.10: angular.js, Ubuntu:26.04:LTS: angular.js

Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 22.0.1, 21.2.17, and 20.3.25, an issue in the @angular/compiler package allows bypassing DOM property sanitization through the use of two-way property bindings. Specifically, when a native DOM property that requires sanitization (such as innerHTML, srcdoc, src, href, data, or sandbox) is bound using the two-way binding syntax (e.g., [(innerHTML)]="value" or bindon-innerHTML="value"), the Angular template compiler failed to apply the appropriate schema-derived sanitizer resolution to the TwoWayProperty operation. As a result, native two-way DOM bindings were emitted without the required sanitizer function, whereas equivalent one-way bindings would be properly sanitized. This flaw enables an attacker who can control the value of a two-way bound sensitive property to bypass Angular's built-in sanitization logic, potentially leading to client-side Cross-Site Scripting (XSS). This vulnerability is fixed in 22.0.1, 21.2.17, and 20.3.25.

Ein Angreifer kann mehrere Schwachstellen in Angular ausnutzen, um beliebigen Programmcode auszuführen, um einen Cross-Site Scripting Angriff durchzuführen, um Informationen offenzulegen, um Sicherheitsvorkehrungen zu umgehen, und um einen Denial of Service Angriff durchzuführen.