cvedb.io
CVE-2026-40165
HIGH · CVSS 8.7
EPSS exploitation probability: 0%
Published 2026-05-21T00:16:28.290 · Last modified 2026-06-17T10:44:48.190

Summary

authentik is an open-source identity provider. Versions 2025.12.4 and prior, and versions 2026.2.0-rc1 through 2026.2.2 were vulnerable to Authentication Bypass through SAML NameID XML Comment Injection. Due to how authentik extracted the NameID value from a SAML assertion, it was possible for an attacker to trick authentik into only seeing a part of the NameID value, potentially allowing an attacker to gain access to other accounts. This issue could be exploited on an authentik instance with a SAML Source, where the attacker had an account on the SAML Source and the ability to modify their NameID value (commonly username or E-mail), and XML Signing was enabled. The attacker could modify the SAML assertion given to authentik by injecting a comment within the NameID value, which effectively

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.