GHSA-gv8r-9rw9-9697 GO-2026-4530
Traefik affected by TLS ClientAuth Bypass on HTTP/3
Critical
Go
- Severity
- 0.0 / 10
- Critical · CVSS 4.0
- Exploit chance (EPSS)
- —
- No score published
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-1395 Dependency on Vulnerable Third-Party Component
- Fix
- Available
- 2 packages have a fixed version
Description
Summary
There is a potential vulnerability in Traefik managing HTTP/3 connections.
More details in the CVE-2025-68121.
Patches
- https://github.com/traefik/traefik/releases/tag/v2.11.37
- https://github.com/traefik/traefik/releases/tag/v3.6.8
Workarounds
No workaround
For more information
If you have any questions or comments about this advisory, please open an issue.
Affected versions
Go
| Package | Vulnerable | Fixed in |
|---|---|---|
| github.com/traefik/traefik | <= 1.7.34 |
No fix yet |
| github.com/traefik/traefik | all versions |
No fix yet |
| github.com/traefik/traefik/v2 | < 2.11.37 |
2.11.37 |
| github.com/traefik/traefik/v3 | < 3.6.8 |
3.6.8 |
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/v2 Go → 2.11.37
- go
go get github.com/traefik/traefik/v2@v2.11.37 && go mod tidy
github.com/traefik/traefik/v3 Go → 3.6.8
- go
go get github.com/traefik/traefik/v3@v3.6.8 && go mod tidy
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- None
- Availability (vulnerable system)
- None
- Confidentiality (subsequent systems)
- High
- Integrity (subsequent systems)
- High
- Availability (subsequent systems)
- None
CVSS 3.1 10.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Weakness
CWE-1395: Dependency on Vulnerable Third-Party Component
The product has a dependency on a third-party component that contains one or more known vulnerabilities.
How to prevent it
- Requirements, Policy: In some industries such as healthcare [REF-1320] [REF-1322] or technologies such as the cloud [REF-1321], it might be unclear about who is responsible for applying patches for third-party vulnerabilities: the vendor, the operator/customer, or a separate service. Clarifying roles and responsibilities can be important to minimize confusion or unnecessary delay when third-party vulnerabilities are disclosed.
- Requirements: Require a Bill of Materials for all components and sub-components of the product. For software, require a Software Bill of Materials (SBOM) [REF-1247] [REF-1311].
- Architecture and Design, Implementation, Integration, Manufacturing: Maintain a Bill of Materials for all components and sub-components of the product. For software, maintain a Software Bill of Materials (SBOM). According to [REF-1247], "An SBOM is a formal, machine-readable inventory of software components and dependencies, information about those components, and their hierarchical relationships."
- Operation, Patching and Maintenance: Actively monitor when a third-party component vendor announces vulnerability patches; fix the third-party component as soon as possible; and make it easy for operators/customers to obtain and apply the patch.
- Operation, Patching and Maintenance: Continuously monitor changes in each of the product's components, especially when the changes indicate new vulnerabilities, end-of-life (EOL) plans, etc.
References
Packages
Other links
Timeline
- Published
- Last updated by the source
Related advisories
| 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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