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TI-2026-49981 Aliases CVE-2026-71324GHSA-3ccp-42pg-hgv6

Traefik: Cross-user response poisoning via proxied CONNECT on Traefik's shared backend keep-alive pool

Priority LOW 39CWE-444Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
—
Confidentiality · integrity · availability
None · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat.

Summary

Traefik is an open source HTTP reverse proxy and load balancer. Prior to 2.11.53, 3.6.24, and 3.7.9, Traefik's default HTTP reverse proxy forwards a plain HTTP/2 or HTTP/3 CONNECT request and its body to an HTTP/1.1 upstream through a shared net/http.Transport. When the upstream answers the CONNECT with a keep-alive non-2xx response and does not drain the body, Traefik returns the desynchronized backend socket to its shared pool and reuses it for other clients. An unauthenticated attacker can use this behavior to make a different client read the attacker's smuggled response, which can include authenticated or private content from another request. The ForwardAuth middleware with forwardBody true and preserveRequestMethod true can re-issue a CONNECT with the buffered body attached, exposing the auth-client pool to the same desynchronization. This issue is fixed in 2.11.53, 3.6.24, and 3.7.9.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01063 64th percentileScored 2026-11-07
Fix Fixed traefik (traefik): 2.11.53, 3.6.24, 3.7.9github.com/traefik/traefik/v2 (Go): 2.11.53+1 more productRed Hat: 1 advisory

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
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 2.11.53; 3.0.0 to before 3.6.24; 3.7.0 to before 3.7.92.11.53, 3.6.24, 3.7.9Patch availableCNA
—github.com/traefik/traefik/v2 (Go)before 2.11.532.11.53Patch availableGHSA-3ccp-42pg-hgv6
—github.com/traefik/traefik/v3 (Go)before 3.6.243.6.24Patch availableGHSA-3ccp-42pg-hgv6
—github.com/traefik/traefik/v3 (Go)3.7.0 to before 3.7.93.7.9Patch availableGHSA-3ccp-42pg-hgv6
—github.com/traefik/traefik (Go)up to 1.7.34—No fix listedGHSA-3ccp-42pg-hgv6
  • traefik Vendortraefik Affected before 2.11.53; 3.0.0 to before 3.6.24; 3.7.0 to before 3.7.9 Fixed in 2.11.53, 3.6.24, 3.7.9 Patch available CNA
  • github.com/traefik/traefik/v2 (Go) Vendor— Affected before 2.11.53 Fixed in 2.11.53 Patch available GHSA-3ccp-42pg-hgv6
  • github.com/traefik/traefik/v3 (Go) Vendor— Affected before 3.6.24 Fixed in 3.6.24 Patch available GHSA-3ccp-42pg-hgv6
  • github.com/traefik/traefik/v3 (Go) Vendor— Affected 3.7.0 to before 3.7.9 Fixed in 3.7.9 Patch available GHSA-3ccp-42pg-hgv6
  • github.com/traefik/traefik (Go) Vendor— Affected up to 1.7.34 Fixed in — No fix listed GHSA-3ccp-42pg-hgv6

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*before 2.11.53; 3.0.0 to before 3.6.24; 3.7.0 to before 3.7.9Vulnerabletraefik
  • cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:* Versions before 2.11.53; 3.0.0 to before 3.6.24; 3.7.0 to before 3.7.9 Vulnerable ·traefik

Remediation

  • Fix · CNA traefik (traefik) Fixed in 2.11.53, 3.6.24, 3.7.9
  • Fix · GHSA-3ccp-42pg-hgv6 github.com/traefik/traefik/v2 (Go) Fixed in 2.11.53 Advisory →
  • Fix · GHSA-3ccp-42pg-hgv6 github.com/traefik/traefik/v3 (Go) Fixed in 3.6.24 Advisory →
  • Fix · GHSA-3ccp-42pg-hgv6 github.com/traefik/traefik/v3 (Go) Fixed in 3.7.9 Advisory →

Red Hat 1 advisory

  • RHSA-2026:90321 Released 2026-10-26 · Red Hat rating Critical
    Red Hat OpenShift Dev Spaces 3.31.0 Release.
    • Red Hat OpenShift Dev Spaces 3.31 registry.redhat.io/devspaces/code-rhel9, registry.redhat.io/devspaces/dashboard-rhel9, registry.redhat.io/devspaces/jetbrains-ide-rhel9 +8

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat OpenShift Dev Spaces 3.31Fixed RHSA-2026:90321
Not affected: 2 products
  • Red Hat OpenShift Dev Spaces 3.31
  • Red Hat OpenShift GitOps

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-71324
  2. 2026-10-03 Alias added: GHSA-3ccp-42pg-hgv6
  3. 2026-10-29 Fix available: Red Hat OpenShift Dev Spaces 3.31 · Red Hat
  4. 2026-10-30 Fix available: RHSA-2026:90321 · Red Hat

References

Patch 7

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