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CVE-2026-54763
7.8 HIGH
- CVSS version (CVSS): 4.0
- Attack Vector (AV): Network (N)
- Attack Complexity (AC): Low (L)
- Attack Requirement (AT): None (N)
- Privileges Required (PR): None (N)
- User Interaction (UI): None (N)
- Vulnerable System Impact Confidentiality (VC): None (N)
- Vulnerable System Impact Integrity (VI): None (N)
- Vulnerable System Impact Availability (VA): None (N)
- Subsequent System Impact Confidentiality (SC): High (H)
- Subsequent System Impact Integrity (SI): High (H)
- Subsequent System Impact Availability (SA): None (N)
- Modified Attack Vector (MAV): Network (N)
- Modified Attack Complexity (MAC): Low (L)
- Modified Attack Requirement (MAT): None (N)
- Modified Privileges Required (MPR): None (N)
- Modified User Interaction (MUI): None (N)
- Modified Vulnerable System Impact Confidentiality (MVC): None (N)
- Modified Vulnerable System Impact Integrity (MVI): None (N)
- Modified Vulnerable System Impact Availability (MVA): None (N)
- Modified Subsequent System Impact Confidentiality (MSC): High (H)
- Modified Subsequent System Impact Integrity (MSI): High (H)
- Modified Subsequent System Impact Availability (MSA): Negligible (N)
- Safety (S): Not Defined (X)
- Automatable (AU): Not Defined (X)
- Recovery (R): Not Defined (X)
- Value Density (V): Not Defined (X)
- Vulnerability Response Effort (RE): Not Defined (X)
- Provider Urgency (U): Not Defined (X)
- Confidentiality Req. (CR): Not Defined (X)
- Integrity Req. (IR): Not Defined (X)
- Availability Req. (AR): Not Defined (X)
- Exploit Maturity (E): Not Defined (X)
Activity log
- Created suggestion
Traefik: headerField underscore-variant identity spoofing in BasicAuth / DigestAuth / ForwardAuth
Traefik is an HTTP reverse proxy and load balancer. Prior to v2.11.51, v3.6.22, and v3.7.6, Traefik's BasicAuth, DigestAuth, and ForwardAuth middlewares strip canonical-cased spoofed identity headers before writing Traefik's own value, but do not account for underscore-variant header names, which many backends normalize identically to dashed forms. An attacker able to reach a protected route can inject an underscore-variant header that survives Traefik's stripping and reaches the backend alongside, or on the unauthenticated ForwardAuth authResponseHeaders path instead of, the value Traefik intended to set, spoofing identity or authorization context. This issue is fixed in versions v2.11.51, v3.6.22, and v3.7.6.
References
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https://github.com/traefik/traefik/security/advisories/GHSA-x677-9fxg-v5c5 x_refsource_CONFIRM
-
https://github.com/traefik/traefik/pull/13262 x_refsource_MISC
Affected products
traefik
- ==>= 3.0.0-beta1, < v3.6.22
- ==>= 3.7.0-ea.1, < v3.7.6
- ==< 2.11.51
Matching in nixpkgs
pkgs.traefik
Modern reverse proxy
Package maintainers
-
@djds djds <git@djds.dev>
-
@vdemeester Vincent Demeester <vincent@sbr.pm>
-
@NickCao Nick Cao <nickcao@nichi.co>