fix(deps): update dependency @angular/compiler to v20.3.18 [security]

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
@angular/compiler (source)	20.3.3 → 20.3.18

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

CVE-2026-32635

A Cross-Site Scripting (XSS) vulnerability has been identified in the Angular runtime and compiler. It occurs when the application uses a security-sensitive attribute (for example href on an anchor tag) together with Angular's ability to internationalize attributes. Enabling internationalization for the sensitive attribute by adding i18n-<attribute> name bypasses Angular's built-in sanitization mechanism, which when combined with a data binding to untrusted user-generated data can allow an attacker to inject a malicious script.

The following example illustrates the issue:

<a href="" i18n-href>Click me</a>

The following attributes have been confirmed to be vulnerable:

• action
• background
• cite
• codebase
• data
• formaction
• href
• itemtype
• longdesc
• poster
• src
• xlink:href

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.

Attack Preconditions

1. The application must use a vulnerable version of Angular.
2. The application must bind unsanitized user input to one of the attributes mentioned above.
3. The bound value must be marked for internationalization via the presence of a i18n-<name> attribute on the same element.

Patches

• 22.0.0-next.3
• 21.2.4
• 20.3.18
• 19.2.20

Workarounds

The primary workaround is to ensure that any data bound to the vulnerable attributes is never sourced from untrusted user input (e.g., database, API response, URL parameters) until the patch is applied, or when it is, it shouldn't be marked for internationalization.

Alternatively, users can explicitly sanitize their attributes by passing them through Angular's DomSanitizer:

import {Component, inject, SecurityContext} from '@​angular/core';
import {DomSanitizer} from '@​angular/platform-browser';

@​Component({
  template: `
    <form action="" i18n-action>
      <button>Submit</button>
    </form>
  `,
})
export class App {
  url: string;

  constructor() {
    const dangerousUrl = 'javascript:alert(1)';
    const sanitizer = inject(DomSanitizer);
    this.url = sanitizer.sanitize(SecurityContext.URL, dangerousUrl) || '';
  }
}

References

• Fix 1
• Fix 2

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Release Notes

angular/angular (@​angular/compiler)

v20.3.18

Compare Source

compiler

Commit	Type	Description
02fbf08890	fix	disallow translations of iframe src

core

Commit	Type	Description
72126f9a08	fix	sanitize translated attribute bindings with interpolations
626bc8bc20	fix	sanitize translated form attributes

v20.3.17

Compare Source

Breaking Changes

core

• Angular now only applies known attributes from HTML in translated ICU content. Unknown attributes are dropped and not rendered.

  (cherry picked from commit 03da204)

core

Commit	Type	Description
7f9de3c118	fix	block creation of sensitive URI attributes from ICU messages

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

v20.3.11

Compare Source

common

Commit	Type	Description
5047849a4a	fix	remove placeholder image listeners once view is removed

compiler

Commit	Type	Description
f9d0818087	fix	support arbitrary nesting in :host-context()
106b9040df	fix	support commas in :host() argument
9419ea348a	fix	support complex selectors in :nth-child()
036c5d2a07	fix	support one additional level of nesting in :host()

core

Commit	Type	Description
dcdd1bcdbb	fix	skip leave animations on view swaps

v20.3.10

Compare Source

compiler-cli

Commit	Description
	make required inputs diagnostic less noisy

migrations

Commit	Description
	Prevent removal of templates referenced with preceding whitespace characters

v20.3.9

Compare Source

v20.3.7

Compare Source

animations

Commit	Type	Description
bd38cd45a5	fix	account for Element.animate exceptions (#​64506)

compiler

Commit	Type	Description
891f180262	fix	correctly compile long numeric HTML entities (#​64297)

compiler-cli

Commit	Type	Description
371274bfc6	fix	missingStructuralDirective diagnostic produces false negatives (#​64470)

core

Commit	Type	Description
4c89a267c3	fix	pass element removal property through in all locations (#​64565)
2fad4d4ab6	fix	prevent duplicate nodes from being retained with fast `animate.leave`` calls (#​64592)

router

Commit	Type	Description
cfd8ed3fff	fix	Fix outlet serialization and parsing with no primary children (#​64505)
182fe78f91	fix	Surface parse errors in Router.parseUrl (#​64503)

v20.3.6

Compare Source

core

Commit	Type	Description
911d6822cb	fix	update animation scheduling (#​64441)

platform-browser

Commit	Type	Description
2ece42866d	fix	DomEventsPlugin should always be the last plugin to be called for supports(). (#​50394)

v20.3.5

Compare Source

compiler-cli

Commit	Type	Description
8dec92ff9f	fix	capture metadata for undecorated fields (#​63957) (#​64317)
c2e817b0ef	perf	fix performance of "interpolated signal not invoked" check (#​64410)

core

Commit	Type	Description
f15cfa4cc4	fix	fixes regression in animate.leave function bindings (#​64413)
d54dd674ca	fix	Prevents early style pruning with leave animations (#​64335)

migrations

Commit	Type	Description
554573e524	fix	migrating input with more than 1 usage in a method (#​64367)
2c79ca0b57	fix	remove error for no matching files in control flow migration (#​64253) (#​64314)

router

Commit	Type	Description
6e4bcc7d22	fix	Scroll restoration should use instant scroll behavior for traversals (#​64299)

v20.3.4

Compare Source

core

Commit	Type	Description
853ed169a8	fix	ensure missing leave animations don't queue leave animations (#​64226)
6fed986b7a	fix	Fixes animations in conjunction with content projection (#​63776)
76fe5599fe	fix	handle undefined CSS time values in parseCssTimeUnitsToMs function (#​64181)
3b959105be	fix	prevent early exit from leave animations when multiple transitions are present (#​64225)

migrations

Commit	Type	Description
65884895ff	fix	preserve component imports when pruning NgModules in standalone migration (#​64186)

---

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⚠️ Artifact update problem

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The artifact failure details are included below:

File name: package.json

Post-upgrade command 'ng update @angular/compiler --from= --to= --migrateOnly --allowDirty --force' has not been added to the allowed list in allowedCommands