Open Redirect Affecting @angular/ssr package, versions >=19.0.0-next.0 <19.2.21>=20.0.0-next.0 <20.3.17>=21.0.0-next.0 <21.1.5>=21.2.0-next.0 <21.2.0-rc.0
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JS-ANGULARSSR-15357598
- published26 Feb 2026
- disclosed25 Feb 2026
- creditVenkatKwest
Introduced: 25 Feb 2026
NewCVE-2026-27738 (opens in a new tab)How to fix?
Upgrade @angular/ssr to version 19.2.21, 20.3.17, 21.1.5, 21.2.0-rc.0 or higher.
Overview
@angular/ssr is a the Angular server side rendering utilities.
Affected versions of this package are vulnerable to Open Redirect via the internal URL processing logic when handling the X-Forwarded-Prefix header. An attacker can cause users to be redirected to arbitrary external domains by supplying a specially crafted header value containing multiple leading slashes, which is insufficiently sanitized before being used in the Location header. This can facilitate large-scale phishing and SEO hijacking attacks.
Note:
This is only exploitable if the application uses Angular SSR, has routes that perform internal redirects, the infrastructure passes the X-Forwarded-Prefix header to the SSR process without sanitization, and the cache does not vary on the X-Forwarded-Prefix header.
Workaround
This vulnerability can be mitigated by sanitizing the X-Forwarded-Prefix header in the server middleware to remove all leading slashes before the Angular engine processes the request.