CVE-2026-55671 ZITADEL: Server-Side Request Forgery (SSRF) and Denylist Bypass in Outgoing HTTP Components

ZITADEL is an open source identity management platform. From 4.0.0-rc.1 through 4.15.1, ZITADEL's HTTP notification channels, OIDC BackChannel Logout, and SAML metadata URL fetches do not consistently validate user-defined URLs against protected denylist handling, allowing server-side requests to...

ZITADEL: Server-Side Request Forgery (SSRF) and Denylist Bypass in Outgoing HTTP Components

Summary A Server-Side Request Forgery SSRF vulnerability was discovered in Zitadel affecting: HTTP Notification Channels: Used as an alternative to SMTP/Twilio configurations, sending payloads to user-defined URLs via HTTP POST webhooks. OIDC BackChannel Logout: Terminates sessions across differe...