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TI-2026-25105 Aliases CVE-2026-32595GHSA-g3hg-j4jv-cwfr

Traefik: BasicAuth Middleware Timing Attack Allows Username Enumeration

Priority LOW 28CWE-208Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Attack requirements
None
Impact type
Information disclosure
Confidentiality · integrity · availability
None · None · None
Fix status
Partial Red Hat: 1 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-208.

Summary

Traefik is an HTTP reverse proxy and load balancer. Versions 2.11.40 and below, 3.0.0-beta1 through 3.6.11, and 3.7.0-ea.1 comtain BasicAuth middleware that allows username enumeration via a timing attack. When a submitted username exists, the middleware performs a bcrypt password comparison taking ~166ms. When the username does not exist, the response returns immediately in ~0.6ms. This ~298x timing difference is observable over the network and allows an unauthenticated attacker to reliably distinguish valid from invalid usernames. This issue is patched in versions 2.11.41, 3.6.11 and 3.7.0-ea.2.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00401 34th percentileScored 2026-11-07
Fix Partial traefik (traefik): 2.11.41, 3.6.11, 3.7.0-ea.2github.com/traefik/traefik/v2 (Go): 2.11.41+1 more productRed Hat: 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
traefiktraefikbefore 2.11.41; 3.0.0-beta1 to before 3.6.11; 3.7.0-ea.1 to before 3.7.0-ea.22.11.41, 3.6.11, 3.7.0-ea.2Patch availableCNA
—github.com/traefik/traefik (Go)up to 1.7.34—No fix listedGHSA-g3hg-j4jv-cwfr
—github.com/traefik/traefik/v2 (Go)before 2.11.412.11.41Patch availableGHSA-g3hg-j4jv-cwfr
—github.com/traefik/traefik/v3 (Go)before 3.6.113.6.11Patch availableGHSA-g3hg-j4jv-cwfr
—github.com/traefik/traefik/v3 (Go)3.7.0-ea.1 to before 3.7.0-ea.23.7.0-ea.2Patch availableGHSA-g3hg-j4jv-cwfr
  • traefik Vendortraefik Affected before 2.11.41; 3.0.0-beta1 to before 3.6.11; 3.7.0-ea.1 to before 3.7.0-ea.2 Fixed in 2.11.41, 3.6.11, 3.7.0-ea.2 Patch available CNA
  • github.com/traefik/traefik (Go) Vendor— Affected up to 1.7.34 Fixed in — No fix listed GHSA-g3hg-j4jv-cwfr
  • github.com/traefik/traefik/v2 (Go) Vendor— Affected before 2.11.41 Fixed in 2.11.41 Patch available GHSA-g3hg-j4jv-cwfr
  • github.com/traefik/traefik/v3 (Go) Vendor— Affected before 3.6.11 Fixed in 3.6.11 Patch available GHSA-g3hg-j4jv-cwfr
  • github.com/traefik/traefik/v3 (Go) Vendor— Affected 3.7.0-ea.1 to before 3.7.0-ea.2 Fixed in 3.7.0-ea.2 Patch available GHSA-g3hg-j4jv-cwfr

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*before 2.11.41; 3.0.0 – 3.6.11Vulnerabletraefik
cpe:2.3:a:traefik:traefik:3.7.0:ea1:*:*:*:*:*:*3.7.0 ea1Vulnerabletraefik
  • cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:* Versions before 2.11.41; 3.0.0 – 3.6.11 Vulnerable ·traefik
  • cpe:2.3:a:traefik:traefik:3.7.0:ea1:*:*:*:*:*:* Versions 3.7.0 ea1 Vulnerable ·traefik

Remediation

  • Fix · CNA traefik (traefik) Fixed in 2.11.41, 3.6.11, 3.7.0-ea.2
  • Fix · GHSA-g3hg-j4jv-cwfr github.com/traefik/traefik/v2 (Go) Fixed in 2.11.41 Advisory →
  • Fix · GHSA-g3hg-j4jv-cwfr github.com/traefik/traefik/v3 (Go) Fixed in 3.6.11 Advisory →
  • Fix · GHSA-g3hg-j4jv-cwfr github.com/traefik/traefik/v3 (Go) Fixed in 3.7.0-ea.2 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat OpenShift Dev SpacesAffectedNo fix yet: Fix deferred

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-32595
  2. 2026-10-03 Alias added: GHSA-g3hg-j4jv-cwfr

References

Patch 1

Advisory 1

Other 4

  • TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
  • TI-2023-25774 Uncontrolled Resource Consumption in Traefik CVSS 3.1HIGH 7.5
  • TI-2025-40914 Traefik doesn't Prevent Path Normalization Bypass in Router + Middleware Rules CVSS 4.0MEDIUM 6.9
  • TI-2022-07529 Authorization header displayed in the debug logs CVSS 3.1MEDIUM 6.5
  • TI-2024-30459 HTTP client can remove the X-Forwarded headers in Traefik CVSS 3.1CRITICAL 9.8
  • TI-2026-60261 Traefik v3.7.0 Authentication Bypass via from-to-www-redirect CVSS 4.0CRITICAL 9.3
See all 83 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences