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