high8.6
CVE-2026-25748
authentik is an open-source identity provider.
Impact
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.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Goauthentik | Authentik | before 2025.10.4 from 2025.12.0 before 2025.12.4 |