authentik is an open-source identity provider. Prior to 2026.2.7, 2026.5.7, and 2026.8.2, an unauthenticated attacker can submit a malformed SAML message to an authentik deployment using SAML in either the identity-provider or SAML source role. The message can stop the worker handling /application/saml/* or /source/saml/*, causing the requests assigned to that worker to fail.
Worker process termination and automatic restart do not destroy database-backed sessions, but continued malicious messages can cause a sustained share of legitimate traffic to fail. Other protocol implementations are not affected. This issue is fixed in versions 2026.2.7, 2026.5.7, and 2026.8.2.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
Weakness Type (CWE)
Vulnerable Products
goauthentik:authentik
References 15
https://docs.goauthentik.io/releases/2026.2#fixed-in-202627
security-advisories@github.com
https://docs.goauthentik.io/releases/2026.5#fixed-in-202657
security-advisories@github.com
https://docs.goauthentik.io/releases/2026.8#fixed-in-202682
security-advisories@github.com
https://github.com/goauthentik/authentik/commit/03d19d63b8d8dd7bc3de7cf6e57c6df…
security-advisories@github.com
https://github.com/goauthentik/authentik/commit/4cf2f803b1c2ef38c224eead375fd05…
security-advisories@github.com
https://github.com/goauthentik/authentik/commit/732adad26bb97361b6bf25ef138df5c…
security-advisories@github.com
https://github.com/goauthentik/authentik/commit/a029f5372295bfeb1e334855f786016…
security-advisories@github.com
https://github.com/goauthentik/authentik/pull/25959
security-advisories@github.com
https://github.com/goauthentik/authentik/pull/25964
security-advisories@github.com
https://github.com/goauthentik/authentik/pull/25969
security-advisories@github.com
https://github.com/goauthentik/authentik/pull/25974
security-advisories@github.com
https://github.com/goauthentik/authentik/releases/tag/version/2026.2.7
security-advisories@github.com
https://github.com/goauthentik/authentik/releases/tag/version/2026.5.7
security-advisories@github.com
https://github.com/goauthentik/authentik/releases/tag/version/2026.8.2
security-advisories@github.com
https://github.com/goauthentik/authentik/security/advisories/GHSA-cxwx-9x59-28qm
security-advisories@github.com