GO-2026-6204 CVE-2026-71326 GHSA-6765-c87h-8mrf

Traefik: BasicAuth singleflight key collision allows authenticated identity spoofing in github.com/traefik/traefik

Low Go

Severity: 0.0 / 10; Low · CVSS 4.0
Exploit chance (EPSS): 0.34%; Chance of exploitation in the next 30 days. Higher than 27.08% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-287 Improper Authentication
Fix: 3.6.25; Upgrade github.com/traefik/traefik/v3 to this version or later

Description

Affected versions

Go

Package	Vulnerable	Fixed in
github.com/traefik/traefik	`all versions`	No fix yet
github.com/traefik/traefik/v2	`all versions`	No fix yet
github.com/traefik/traefik/v3	`>= 3.6.11, < 3.6.25`	`3.6.25`
github.com/traefik/traefik/v3	`>= 3.7.0, < 3.7.10`	`3.7.10`
github.com/traefik/traefik/v3	`>= 3.6.11, < 3.6.25` `>= 3.7.0, < 3.7.10`	`3.6.25` `3.7.10`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

github.com/traefik/traefik/v3 Go → `3.6.25`

go

go get github.com/traefik/traefik/v3@v3.6.25 && go mod tidy

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

Attack vector: Network
Attack complexity: Low
Attack requirements: Present
Privileges required: High
User interaction: None
Confidentiality (vulnerable system): Low
Integrity (vulnerable system): Low
Availability (vulnerable system): None
Confidentiality (subsequent systems): None
Integrity (subsequent systems): None
Availability (subsequent systems): None

CVSS 3.1 3.8

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

Attack vector: Network
Attack complexity: Low
Privileges required: High
User interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: None

Weakness

CWE-287: Improper Authentication

When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

How to prevent it

Architecture and Design: Use an authentication framework or library such as the OWASP ESAPI Authentication feature.

References

Packages

github.com/traefik/traefik

Timeline

Aug 6, 2026 Published
Sep 16, 2026 Last updated by the source
Oct 31, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GO-2026-6558 Traefik: BasicAuth singleflight coalescing reintroduces an unauthenticated username-enumeration timing oracle	Medium	Also affects github.com/traefik/traefik
GHSA-f52w-8j3h-j724 Traefik: Rootless HTTP/1 request-target routes as "/" but is forwarded verbatim, bypassing path-scoped routing, middleware guards and access logging	High	Also affects github.com/traefik/traefik
GHSA-w4v4-9rw7-5326 Traefik: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') and Incorrect Authorization	Critical	Also affects github.com/traefik/traefik
GHSA-qqjf-53cj-pwvv Traefik HTTP/3 Backend NTLM Connection Reuse	Critical	Also affects github.com/traefik/traefik
GO-2026-6467 Traefik entrypoint header-name sanitization bypassed via request trailers	High	Also affects github.com/traefik/traefik
GHSA-rf44-j88r-hh8c Traefik: ForwardAuth identity spoofing via dot-form header alias	High	Also affects github.com/traefik/traefik
GHSA-7ghq-v6jf-g56c Traefik: respondingTimeouts.readTimeout is not applied to HTTP/3, leaving slow-body uploads unbounded	Medium	Also affects github.com/traefik/traefik
GHSA-62fc-8686-hfmq Traefik: `allowCrossNamespace=false` bypass via `@kubernetescrd` TraefikService backendRef	Medium	Also affects github.com/traefik/traefik

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