Auth bypass in Zitadel
CVE-2026-109372
ZITADEL 4.x before 4.19.2 and 3.x through 3.4.15 contains an authentication bypass in the SAML identity-provider intent callback, which verifies the assertion signature using the provider named in the request URL but resolves the user from the login intent without checking they match. Attackers with organization-administrator permission can register a SAML provider with their own signing key to obtain authenticated sessions as any user linked to another SAML provider on the instance, including in other organizations.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/zitadel/zitadel/security/advisories/GHSA-x4c7-fpcx-w9q6 (vendor-advisory)
- www.vulncheck.com/advisories/zitadel-3.0.0-before-4.19.2-account-takeover-via-s… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-109372?
- CVE-2026-109372 is a high-severity vulnerability in Zitadel, classified under Improper Authentication. CVSS score: 8.7/10. Published 2026-10-12.
- How severe is CVE-2026-109372?
- High severity. CVSS v3 base score is 8.7 out of 10.