chore(deps): update dependency @angular/compiler to v20.3.16 [security]

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
@angular/compiler (source)	20.3.11 → 20.3.16
@angular/compiler (source)	17.3.8 → 20.3.16

GitHub Vulnerability Alerts

CVE-2025-66412

A Stored Cross-Site Scripting (XSS) vulnerability has been identified in the Angular Template Compiler. It occurs because the compiler's internal security schema is incomplete, allowing attackers to bypass Angular's built-in security sanitization. Specifically, the schema fails to classify certain URL-holding attributes (e.g., those that could contain javascript: URLs) as requiring strict URL security, enabling the injection of malicious scripts.

Additionally, a related vulnerability exists involving SVG animation elements (<animate>, <set>, <animateMotion>, <animateTransform>). The attributeName attribute on these elements was not properly validated, allowing attackers to dynamically target security-sensitive attributes like href or xlink:href on other elements. By binding attributeName to "href" and providing a javascript: URL in the values or to attribute, an attacker could bypass sanitization and execute arbitrary code.

Attributes confirmed to be vulnerable include:

• SVG-related attributes: (e.g., xlink:href), and various MathML attributes (e.g., math|href, annotation|href).
• SVG animation attributeName attribute when bound to "href" or "xlink:href".

When template binding is used to assign untrusted, user-controlled data to these attributes (e.g., [attr.xlink:href]="maliciousURL" or <animate [attributeName]="'href'" [values]="maliciousURL">), the compiler incorrectly falls back to a non-sanitizing context or fails to block the dangerous attribute assignment. This allows an attacker to inject a javascript:URL payload. Upon user interaction (like a click) on the element, or automatically in the case of animations, the malicious JavaScript executes in the context of the application's origin.

Impact

When exploited, this vulnerability allows an attacker to execute arbitrary code within the context of the vulnerable application's domain. This enables:

• Session Hijacking: Stealing session cookies and authentication tokens.
• Data Exfiltration: Capturing and transmitting sensitive user data.
• Unauthorized Actions: Performing actions on behalf of the user.

Patches

• 19.2.17
• 20.3.15
• 21.0.2

Attack Preconditions

• The victim's Angular application must render data derived from untrusted input (e.g., from a database or API) and bind it to one of the unsanitized URL attributes or the attributeName of an SVG animation element.
• The victim must perform a user interaction (e.g., clicking) on the compromised element for the stored script to execute, or the animation must trigger the execution.

Workarounds

If you cannot upgrade, you can workaround the issue by ensuring that any data bound to the vulnerable attributes is never sourced from untrusted user input (e.g., database, API response, URL parameters).

• Avoid Affected Template Bindings: Specifically avoid using template bindings (e.g., [attr.xlink:href]="maliciousURL") to assign untrusted data to the vulnerable SVG/MathML attributes.
• Avoid Dynamic attributeName on SVG Animations: Do not bind untrusted data to the attributeName attribute of SVG animation elements (<animate>, <set>, etc.).
• Enable Content Security Policy (CSP): Configure a robust CSP header that disallows javascript: URLs.

CVE-2026-22610

A Cross-Site Scripting (XSS) vulnerability has been identified in the Angular Template Compiler. The vulnerability exists because Angular’s internal sanitization schema fails to recognize the href and xlink:href attributes of SVG <script> elements as a Resource URL context.

In a standard security model, attributes that can load and execute code (like a script's source) should be strictly validated. However, because the compiler does not classify these specific SVG attributes correctly, it allows attackers to bypass Angular's built-in security protections.

When template binding is used to assign user-controlled data to these attributes for example, <script [attr.href]="userInput"> the compiler treats the value as a standard string or a non-sensitive URL rather than a resource link. This enables an attacker to provide a malicious payload, such as a data:text/javascript URI or a link to an external malicious script.

Impact

When successfully exploited, this vulnerability allows for arbitrary JavaScript execution within the context of the victim's browser session. This can lead to:

• Session Hijacking: Stealing session cookies, localStorage data, or authentication tokens.
• Data Exfiltration: Accessing and transmitting sensitive information displayed within the application.
• Unauthorized Actions: Performing state-changing actions (like clicking buttons or submitting forms) on behalf of the authenticated user.

Attack Preconditions

1. The victim application must explicitly use SVG <script> elements within its templates.
2. The application must use property or attribute binding (interpolation) for the href or xlink:href attributes of those SVG scripts.
3. The data bound to these attributes must be derived from an untrusted source (e.g., URL parameters, user-submitted database entries, or unsanitized API responses).

Patches

• 19.2.18
• 20.3.16
• 21.0.7
• 21.1.0-rc.0

Workarounds

Until the patch is applied, developers should:

• Avoid Dynamic Bindings: Do not use Angular template binding (e.g., [attr.href]) for SVG <script> elements.
• Input Validation: If dynamic values must be used, strictly validate the input against a strict allowlist of trusted URLs on the server side or before it reaches the template.

Resources

• https://github.com/angular/angular/pull/66318

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Release Notes

angular/angular (@​angular/compiler)

v20.3.16

Compare Source

core

Commit	Type	Description
c2c2b4aaa8	fix	sanitize sensitive attributes on SVG script elements

v20.3.15

Compare Source

compiler

Commit	Type	Description
d1ca8ae043	fix	prevent XSS via SVG animation attributeName and MathML/SVG URLs

v20.3.14

Compare Source

http

Commit	Type	Description
0276479e7d	fix	prevent XSRF token leakage to protocol-relative URLs

v20.3.13

Compare Source

v20.3.12

Compare Source

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