authentik: Authentication bypass via assertion confusion in SAML sources
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 2026.2.7, 2026.5.7, 2026.8.2
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: total
Summary
authentik is an open-source identity provider. Prior to 2026.2.7, 2026.5.7, and 2026.8.2, an authentik SAML Source verifies an assertion's signature and validity period but does not ensure that the identity provider issued the assertion for that Source or in response to a login request from that Source. The SAML Source also does not record already accepted assertions, allowing replay. An unauthenticated actor who possesses such a valid assertion can use an assertion intended for another service provider or reuse an earlier assertion to authenticate as the user named by the assertion. Only SAML Sources are affected; SAML Providers and other Source types are not affected. This issue is fixed in versions 2026.2.7, 2026.5.7, and 2026.8.2.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- goauthentik authentik
fixed in 2026.2.7; From 2026.5.0 · fixed in 2026.5.7; From 2026.8.0 · fixed in 2026.8.2
- authentikBitnami
fixed in 2026.2.7; From 2026.5.0 · fixed in 2026.5.7; From 2026.8.0 · fixed in 2026.8.2