What’s Vulnerable › Vulnerabilities

CVE-2026-25748: authentik has a forward authentication bypass with broken cookie

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-02-12 · updated 2026-06-17
• Weakness: CWE-287

Description

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

• goauthentik authentik: before 2025.10.4; from 2025.12.0 before 2025.12.4 — fixed in 2025.10.4, 2025.12.4

How to fix

Upgrade to a fixed version: goauthentik authentik 2025.10.4, 2025.12.4. Check the vendor advisory for mitigations.

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

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