Evidence used
- No CISA KEV confirmation is currently recorded.
- The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
- EPSS is 0.27% for the current model date.
BlackTreeCVE Intelligencegoauthentik · authentik
Official source article: GitHub GHSA-CQJ8-FXXF-9PG7 ↗. Check the applicable product and release in the original source.
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Fix not verifiedauthentik 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.
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.
The affected component does not establish the requesting party's identity reliably before granting access.
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
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.
The affected component does not establish the requesting party's identity reliably before granting access.
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
CWE-287: Improper Authentication. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
Operational remediation based on structured source evidence.
Published 24 Sept 2026 · Last source change 24 Sept 2026, 17:15 UTC · CWE-287 · Improper Authentication
Core structured fields are present and their contributing authorities are shown above.