Executive brief
ZITADEL, an open-source identity management platform, is vulnerable to a security flaw where certain features—such as notification webhooks and logout processes—can be manipulated to send unauthorized requests to internal systems. An attacker with low-level access could use this to probe the organization's internal network, scan for open ports, or interact with sensitive internal services that are not intended to be public. This could lead to the exposure of internal network architecture or unauthorized access to internal infrastructure.
Technical details
A Server-Side Request Forgery (SSRF) vulnerability exists in ZITADEL's outgoing HTTP components, specifically within HTTP notification channels, OIDC BackChannel Logout, and SAML metadata URL fetches. The application fails to consistently validate user-supplied URLs against a protected denylist, and the existing denylist mechanism was found to be bypassable via DNS rebinding, HTTP redirects, and protocol downgrades (HTTPS to HTTP). An authenticated attacker with low privileges can provide malicious URLs pointing to loopback addresses, internal IP ranges, or cloud metadata services (IMDS). This allows for internal network mapping and interaction with unauthorized internal services. The fix, introduced in version 4.15.2, implements a hardened HTTP client with DNS rebinding protection and a unified denylist.
Affected products
- ZITADEL ZITADEL 4.0.0-rc.1 through 4.15.1; 3.0.0 through 3.4.11
Timeline
- 2026-06-15: patched: Fix committed to repository
- 2026-06-17: advisory: GitHub Security Advisory published and version 4.15.2 released
- 2026-07-10: disclosed: CVE published to NVD