GHSA-f3m7-gqxr-g87x
MEDIUMGHSA-f3m7-gqxr-g87x is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in @angular/core. O3 Security confirms whether GHSA-f3m7-gqxr-g87x is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Angular: Template and Attribute Namespace Sanitization Bypass (XSS)
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
@angular/corenpmDescription
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
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @angular/core | ≥ 21.0.0-next.0&&< 21.2.15 | 21.2.15 |
| 📦npm | @angular/core | ≥ 22.0.0-next.0&&< 22.0.0-rc.2 | 22.0.0-rc.2 |
| 📦npm | @angular/core | ≥ 20.0.0-next.0&&< 20.3.22 | 20.3.22 |
| 📦npm | @angular/core | ≥ 19.0.0-next.0&&< 19.2.22 | 19.2.22 |
| 📦npm | @angular/core | all versions | No fix |
| 📦npm | @angular/compiler | ≥ 21.0.0-next.0&&< 21.2.15 | 21.2.15 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @angular/core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update @angular/core to 21.2.15 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-f3m7-gqxr-g87x is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-f3m7-gqxr-g87x is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-f3m7-gqxr-g87x. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-f3m7-gqxr-g87x in your dependencies?
O3 detects GHSA-f3m7-gqxr-g87x across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.