CVE-2026-25748

EUVD-2026-6702
authentik is an open-source identity provider. Prior to 2025.10.4 and 2025.12.4, with a malformed cookie it was possible to bypass authentication when using forward authentication in the authentik Proxy Provider when used in conjunction with Traefik or Caddy as reverse proxy. When a malicious cookie was used, none of the authentik-specific X-Authentik-* headers were set which depending on application can grant access to an attacker. authentik 2025.10.4 and 2025.12.4 fix this issue.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
8.6 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
GitHub_MCNA
8.6 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 8%
Affected Products (NVD)
VendorProductVersion
goauthentikauthentik
𝑥
< 2025.10.4
goauthentikauthentik
2025.12.0 ≤
𝑥
< 2025.12.4
𝑥
= Vulnerable software versions
Common Weakness Enumeration
References
https://github.com/goauthentik/authentik/releases/tag/version%2F2025.10.4
https://github.com/goauthentik/authentik/releases/tag/version%2F2025.12.4
https://github.com/goauthentik/authentik/security/advisories/GHSA-fj56-5763-j8pp