GHSA-f3m7-gqxr-g87x is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in @angular/core. A fix is available for @angular/core — see the affected versions and patch details below.
Angular: Template and Attribute Namespace Sanitization Bypass (XSS)
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-f3m7-gqxr-g87x.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-f3m7-gqxr-g87x plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 374,847 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@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 | 21.2.15npm install @angular/core@21.2.15 |
| 📦npm | @angular/core | ≥ 22.0.0-next.0&&< 22.0.0-rc.2 | 22.0.0-rc.2npm install @angular/core@22.0.0-rc.2 |
| 📦npm | @angular/core | ≥ 20.0.0-next.0&&< 20.3.22 | 20.3.22npm install @angular/core@20.3.22 |
| 📦npm | @angular/core | ≥ 19.0.0-next.0&&< 19.2.22 | 19.2.22npm install @angular/core@19.2.22 |
| 📦npm | @angular/core | all versions | No fix |
| 📦npm | @angular/compiler | ≥ 21.0.0-next.0&&< 21.2.15 | 21.2.15npm install @angular/compiler@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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-f3m7-gqxr-g87x can be triaged on real exposure rather than presence alone.
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 Security finds GHSA-f3m7-gqxr-g87x across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.