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GO-2026-6558 CVE-2026-88010 GHSA-8fcf-v89g-xpg6

Traefik: BasicAuth singleflight coalescing reintroduces an unauthenticated username-enumeration timing oracle

Medium Go
Severity
0.0 / 10
Medium · CVSS 4.0
Exploit chance (EPSS)
0.31%
Chance of exploitation in the next 30 days. Higher than 23.52% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-208 Observable Timing Discrepancy
Fix
3.7.13
Upgrade Traefik to this version or later

Description

Traefik: BasicAuth singleflight coalescing reintroduces an unauthenticated username-enumeration timing oracle.

NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions.

(If this is causing false-positive reports from vulnerability scanners, please suggest an edit to the report.)

The additional affected modules and versions are: github.com/traefik/traefik from v3.6.11 before v3.7.13.

Affected versions

Go

PackageVulnerableFixed in
Traefik
>= 3.6.11, < 3.7.13
3.7.13
github.com/traefik/traefik
all versions
No fix yet

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.

Traefik Go → 3.7.13

go
go get Traefik@v3.7.13 && go mod tidy

Severity breakdown

CVSS 4.0 0.0

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

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

CVSS 3.1 5.3

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

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

Weakness

CWE-208: Observable Timing Discrepancy

Two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not.

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
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
GO-2026-6209
Traefik: Gateway API route identity collision allows cross-namespace backend hijacking
High Also affects github.com/traefik/traefik
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