Auth bypass in Zitadel
CVE-2026-55672
ZITADEL is an open source identity management platform. Prior to 3.4.12 and 4.15.2, ZITADEL's OAuth2 and OIDC CodeExchange, RefreshToken, and device token flows fail to verify that the requesting client matches the client that initiated the authorization flow, allowing intercepted grants or refresh tokens to be exchanged under a different client. This issue is fixed in versions 3.4.12 and 4.15.2.
Vulnerability class: Broken Authentication
EPSS: 0.004 (35.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.
Affected products
- Zitadel — versions >= 4.0.0-rc.1, < 4.15.2, < 3.4.12
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-55672?
- CVE-2026-55672 is a high-severity vulnerability in Zitadel, classified under Improper Authentication. CVSS score: 7.4/10. Published 2026-07-10.
- How severe is CVE-2026-55672?
- High severity. CVSS v3 base score is 7.4 out of 10.