GHSA-pr34-2v5x-6qjq
CRITICALZITADEL has 1-Click Account Takeover via XSS in /saml-post Endpoint
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.
Blast Radius
github.com/zitadel/zitadel🐹github.com/zitadel/zitadel/v2Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
A vulnerability was discovered in Zitadel's login V2 interface that allowed a possible account takeover.
Impact
Zitadel exposes an HTTP endpoint named /saml-post. This endpoint is used for handling requests to SAML IdPs and accepts two HTTP GET parameters: url and id. When these parameters are supplied, users’ browsers auto-submit an HTTP POST request to the provided url parameter.
The endpoint insecurely redirects users using the provided url GET parameter. As a result, by specifying a javascript: scheme, malicious JS code could be executed on Zitadel users’ browsers.
The endpoint also reflects user-supplied input in the server response, without HTML-encoding it. As a result, it is possible to inject arbitrary HTML code, which again leads to malicious JS code execution in the Zitadel users’ browsers.
An unauthenticated remote attacker can exploit these XSS vulnerabilities, and thus, execute malicious JavaScript code on behalf of Zitadel users. By doing so, such an attacker could reset the password of their victims, and take over their accounts.
It's important to note that this specific attack vector is mitigated for accounts that have Multi-Factor Authentication (MFA) or Passwordless authentication enabled.
Affected Versions
Systems running one of the following versions are affected:
- 4.x:
4.0.0through4.11.1(including RC versions)
Important Note: Although this /saml-post endpoint is used when Zitadel is integrated with a SAML Identity Provider (IdP), the vulnerability in this finding does not require Zitadel to be configured with a SAML IdP. Consequently, Zitadel is vulnerable in its default, out-of-the-box configuration.
Patches
The vulnerability has been addressed in the latest releases. The patch reworked the integration of SAML IdPs and the /saml-post endpoint no longer exists. Additionally, the page to change the password, now always requires the user's current password regardless of the state of the authenticated session.
4.x: Upgrade to >= 4.12.0
Workarounds
The recommended solution is to upgrade to a patched version. If an upgrade is not possible and no SAML IdP integration is needed, a WAF or reverse proxy rule can be deployed to prevent access to the endpoint.
Questions
If there are any questions or comments about this advisory, please email them to [email protected]
Credits
ZITADEL extends thanks once again to Amit Laish from GE Vernova for finding and reporting the vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/zitadel/zitadel | ≥ 4.0.0&&< 4.12.0 | 4.12.0 |
| 🐹Go | github.com/zitadel/zitadel/v2 | ≥ 4.0.0&&< 4.12.0 | 4.12.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/zitadel/zitadel. 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 github.com/zitadel/zitadel to 4.12.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-pr34-2v5x-6qjq 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-pr34-2v5x-6qjq 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-pr34-2v5x-6qjq. 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-pr34-2v5x-6qjq in your dependencies?
O3 detects GHSA-pr34-2v5x-6qjq across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.