CVE-2026-50557Medium▾ Sunlit

Angular: Template and Attribute Namespace Sanitization Bypass (XSS)

▾ Sunlit zone — Low / medium · no exploitation signal

Depth score28/ 100 · Low

impact 27.5 · likelihood 0.1 · exploitation 0

⚡ Agent-ready:Raw markdown ↗JSON ↗

Proof of concept

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Published

Jun 15, 2026

Updated

Jun 15, 2026

CVSS

—

Vendor

angular

Product

@angular/core

CWE

CWE-79

Depth score

28 · Low

EPSS

0.34% · p28

Platforms

—

Source

GHSA

Vector

—

EPSS history

Exploit-prediction probability, daily snapshots since Jul 7.

0.2% → 0.3%▲ 0.1%

Timeline

Disclosure to exploitation, from the record and what we observed since indexing it.

3 events · 70 days

Jun 15, 2026Published
Disclosed via GHSA
Jul 7, 2026EPSS first tracked
0.2%
Aug 24, 2026EPSS peak
0.2% → 0.3%

angular CWE-79 #ghsa #npm

Affected

@angular/core >= 21.0.0-next.0, < 21.2.15
@angular/core >= 22.0.0-next.0, < 22.0.0-rc.2
@angular/core >= 20.0.0-next.0, < 20.3.22
@angular/core >= 19.0.0-next.0, < 19.2.22
@angular/core <= 18.2.14
@angular/compiler >= 21.0.0-next.0, < 21.2.15
@angular/compiler >= 22.0.0-next.0, < 22.0.0-rc.2
@angular/compiler >= 20.0.0-next.0, < 20.3.22
@angular/compiler >= 19.0.0-next.0, < 19.2.22
@angular/compiler <= 18.2.14

Patched in

@angular/core 21.2.15
@angular/core 22.0.0-rc.2
@angular/core 20.3.22
@angular/core 19.2.22
@angular/compiler 21.2.15
@angular/compiler 22.0.0-rc.2
@angular/compiler 20.3.22
@angular/compiler 19.2.22

Full technical detail▾

Overview

An issue in the @angular/compiler and @angular/core packages allows bypassing element and attribute sanitization/validation through specific namespace workarounds.

Specifically, namespaced script elements (e.g., <svg:script> or <:svg:script>) were not properly identified as script elements by the Angular template preparser, allowing them to pass through template compilation without being stripped.

Furthermore, security context schema mappings for element attributes did not consistently handle attributes within namespaced elements (like SVG and MathML), opening up gaps where malicious namespaced attributes could bypass runtime and compile-time sanitizers.

Combined, these flaws enable an attacker who can inject or supply a template/tag structure with custom namespaces to bypass Angular's script-stripping logic and attribute sanitizers, leading to client-side Cross-Site Scripting (XSS).

Impact

Any Angular application that compiles user-controlled templates at runtime, or relies on sanitization of namespaced elements/attributes, is vulnerable to this security bypass.

Once exploited, this allows a malicious actor to inject a namespaced script element or dynamic attribute bindings, bypassing core sanitization constraints to execute arbitrary JavaScript within the target user's browser context. This could lead to session hijacking, sensitive data exposure, or unauthorized actions on behalf of the user.

Attack Preconditions

To successfully exploit these vulnerabilities, the following environment parameters and application states must all concurrently exist:

User-Controlled Template Input: The application must accept user-controlled inputs that are directly processed by the Angular template compiler at runtime.
Namespace Parsing Support: The input structure must employ custom namespace prefixes (such as <svg:script>) to evade standard tag-name blocklists/checks.
Absence of Additional Context Sanitization: The application does not perform separate input sanitization before feeding values to the Angular compiler.

Patches

22.0.0-rc.2
21.2.15
20.3.22
19.2.23

Affected packages

@angular/core >= 21.0.0-next.0, < 21.2.15
@angular/core >= 22.0.0-next.0, < 22.0.0-rc.2
@angular/core >= 20.0.0-next.0, < 20.3.22
@angular/core >= 19.0.0-next.0, < 19.2.22
@angular/core <= 18.2.14
@angular/compiler >= 21.0.0-next.0, < 21.2.15
@angular/compiler >= 22.0.0-next.0, < 22.0.0-rc.2
@angular/compiler >= 20.0.0-next.0, < 20.3.22
@angular/compiler >= 19.0.0-next.0, < 19.2.22
@angular/compiler <= 18.2.14

Remediation

Upgrade to a patched release:

@angular/core 21.2.15
@angular/core 22.0.0-rc.2
@angular/core 20.3.22
@angular/core 19.2.22
@angular/compiler 21.2.15
@angular/compiler 22.0.0-rc.2
@angular/compiler 20.3.22
@angular/compiler 19.2.22

References

Related vulnerabilities

Connected by shared product, vendor, weakness, or advisory.

#ghsa#npm

Overview

An issue in the @angular/compiler and @angular/core packages allows bypassing element and attribute sanitization/validation through specific namespace workarounds.

Impact

Any Angular application that compiles user-controlled templates at runtime, or relies on sanitization of namespaced elements/attributes, is vulnerable to this security bypass.

Attack Preconditions

To successfully exploit these vulnerabilities, the following environment parameters and application states must all concurrently exist:

User-Controlled Template Input: The application must accept user-controlled inputs that are directly processed by the Angular template compiler at runtime.

Namespace Parsing Support: The input structure must employ custom namespace prefixes (such as <svg:script>) to evade standard tag-name blocklists/checks.

Absence of Additional Context Sanitization: The application does not perform separate input sanitization before feeding values to the Angular compiler.

Patches

22.0.0-rc.2

21.2.15

20.3.22

19.2.23

Affected packages

@angular/core >= 21.0.0-next.0, < 21.2.15

@angular/core >= 22.0.0-next.0, < 22.0.0-rc.2

@angular/core >= 20.0.0-next.0, < 20.3.22

@angular/core >= 19.0.0-next.0, < 19.2.22

@angular/core <= 18.2.14

@angular/compiler >= 21.0.0-next.0, < 21.2.15

@angular/compiler >= 22.0.0-next.0, < 22.0.0-rc.2

@angular/compiler >= 20.0.0-next.0, < 20.3.22

@angular/compiler >= 19.0.0-next.0, < 19.2.22

@angular/compiler <= 18.2.14