What is the CVSS score of CVE-2026-25748?

CVE-2026-25748 has a CVSS 3.1 base score of 8.6 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N. EPSS exploitation probability: 0.0%.

Which versions of Authentik are affected by CVE-2026-25748?

A critical authentication bypass vulnerability in authentik's proxy provider affects organizations using forward authentication with Traefik or Caddy reverse proxies.

How to fix or mitigate CVE-2026-25748?

Within 24 hours: Identify all instances of authentik Proxy Provider deployed with Traefik or Caddy and document them; assess whether any are protecting production systems. Within 7 days: Implement compensating controls (WAF cookie validation rules, restrict cookie size/format, network segmentation) and monitor authentication logs for suspicious cookie patterns. Within 30 days: Upgrade to authentik 2025.10.4 or 2025.12.4 once patches are released, or migrate to an alternative authentication method if patching is delayed beyond acceptable risk tolerance.

Authentik CVE-2026-25748

HIGH

Improper Authentication (CWE-287)

2026-02-12 security-advisories@github.com

Authentication Bypass Authentik

8.6

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

8.6 HIGH

AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

None

Availability

None

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:02 vuln.today

CVE Published

Feb 12, 2026 - 20:16 nvd

HIGH 8.6

DescriptionGitHub Advisory

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.

AnalysisAI

Authentik Proxy Provider allows authentication bypass through malformed cookies when deployed with Traefik or Caddy as a reverse proxy, enabling attackers to access protected applications by circumventing forward authentication checks. The vulnerability stems from improper cookie validation that prevents the setting of required authentik-specific X-Authentik-* headers, potentially granting unauthorized access depending on the backend application's configuration. Affected versions prior to 2025.10.4 and 2025.12.4 are vulnerable; patches are available in the specified releases.

Technical ContextAI

Classified as CWE-287 (Improper Authentication). Affects Authentik. 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.