GHSA-q63q-pgmf-mxhr
Fix: angular/angular-cli@5271547GHSA-q63q-pgmf-mxhr is a Server-Side Request Forgery (SSRF) vulnerability in @angular/ssr. O3 Security confirms whether GHSA-q63q-pgmf-mxhr is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Angular SSR has a Server-Side Request Forgery (SSRF) flaw
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
@angular/ssrnpmDescription
Impact
The vulnerability is a Server-Side Request Forgery (SSRF) flaw within the URL resolution mechanism of Angular's Server-Side Rendering package (@angular/ssr).
The function createRequestUrl uses the native URL constructor. When an incoming request path (e.g., originalUrl or url) begins with a double forward slash (//) or backslash (\\), the URL constructor treats it as a schema-relative URL. This behavior overrides the security-intended base URL (protocol, host, and port) supplied as the second argument, instead resolving the URL against the scheme of the base URL but adopting the attacker-controlled hostname.
This allows an attacker to specify an external domain in the URL path, tricking the Angular SSR environment into setting the page's virtual location (accessible via DOCUMENT or PlatformLocation tokens) to this attacker-controlled domain. Any subsequent relative HTTP requests made during the SSR process (e.g., using HttpClient.get('assets/data.json')) will be incorrectly resolved against the attacker's domain, forcing the server to communicate with an arbitrary external endpoint.
Exploit Scenario
A request to http://localhost:4200//attacker-domain.com/some-page causes Angular to believe the host is attacker-domain.com. A relative request to api/data then becomes a server-side request to http://attacker-domain.com/api/data.
Patches
@angular/ssr19.2.18@angular/ssr20.3.6@angular/ssr21.0.0-next.8
Mitigation
The application's internal location must be robustly determined from the incoming request. The fix requires sanitizing or validating the request path to prevent it from being interpreted as a schema-relative URL (i.e., ensuring it does not start with //).
Server-Side Middleware
If you can't upgrade to a patched version, implement a middleware on the Node.js/Express server that hosts the Angular SSR application to explicitly reject or sanitize requests where the path begins with a double slash (//).
Example (Express/Node.js):
// Place this middleware before the Angular SSR handler
app.use((req, res, next) => {
if (req.originalUrl?.startsWith('//')) {
// Sanitize by forcing a single slash
req.originalUrl = req.originalUrl.replace(/^\/\/+/, '/');
req.url = req.url.replace(/^\/\/+/, '/');
}
next();
});
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @angular/ssr | ≥ 19.0.0-next.0&&< 19.2.18 | 19.2.18 |
| 📦npm | @angular/ssr | ≥ 20.0.0-next.0&&< 20.3.6 | 20.3.6 |
| 📦npm | @angular/ssr | ≥ 21.0.0-next.0&&< 21.0.0-next.8 | 21.0.0-next.8 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @angular/ssr. 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/ssr to 19.2.18 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-q63q-pgmf-mxhr 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-q63q-pgmf-mxhr 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-q63q-pgmf-mxhr. 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-q63q-pgmf-mxhr in your dependencies?
O3 detects GHSA-q63q-pgmf-mxhr across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.