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

Severity: low (CVSS 2.3 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-10 · updated 2026-07-14
Weakness: CWE-918

Description

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 loopback, internal IP, link-local, or redirected endpoints through DNS rebinding, redirects, or protocol downgrades. This issue is fixed in version 4.15.2.

Affected products

zitadel: before 4.15.2

References

https://github.com/zitadel/zitadel/commit/b6f78086913b8d916bce9ab2e049ab0d84f947fd
https://github.com/zitadel/zitadel/releases/tag/v4.15.2
https://github.com/zitadel/zitadel/security/advisories/GHSA-29jh-8cfq-rr8x

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