ETK-2026-978Zero's internal tracking ID, independent of the CVE number.
validatedZero produced an exploit or a check.description
Traefik versions with NTLM or Kerberos backend authentication can incorrectly reuse backend connection state across services that have different ServersTransport TLS configurations. An unauthenticated client using a persistent connection may cause requests to one backend to bypass its intended TLS validation settings or use another backend's client certificate.
mitigation
Upgrade Traefik v2 to v2.11.58 or later, or upgrade v3 to v3.7.14 or later. Move deployments on v3.0 through v3.6 to v3.7.14, as those releases are no longer patched.
fixed in v2.11.58, v3.7.14
outcome
Check only, differential: the check fires on the vulnerable build and is silent on the patched one.
source signals
Public signals that triggered or updated the pipeline. These are inputs for the deltas above.
- 2026-10-07 08:47Zghsa: trigger signal, started the run
this entry in the feed
GET /api/v1/feed/ETK-2026-978
{ "etk_id": "ETK-2026-978", "cve_id": null, "display_id": "ETK-2026-978", "ghsa_id": "GHSA-cw35-4q88-3rmp", "euvd_id": null, "status": "published", "anchor_state": "awaiting_cve", "title": "Traefik backend connection reuse TLS policy bypass", "summary": "Traefik versions with NTLM or Kerberos backend authentication can incorrectly reuse backend connection state across services that have different ServersTransport TLS configurations. An unauthenticated client using a persistent connection may cause requests to one backend to bypass its intended TLS validation settings or use another backend's client certificate.", "mitigation": "Upgrade Traefik v2 to v2.11.58 or later, or upgrade v3 to v3.7.14 or later. Move deployments on v3.0 through v3.6 to v3.7.14, as those releases are no longer patched.", "vendor": "go", "product": "go:Traefik", "affected": [ { "affected_notes": [], "affected_ranges": [ ">= v2.11.0, <= v2.11.57" ], "ecosystem": "go", "fixed_versions": [ "v2.11.58" ], "package_name": "Traefik", "purl": "pkg:golang/Traefik" }, { "affected_notes": [], "affected_ranges": [ ">= v3.0.0, <= v3.7.13" ], "ecosystem": "go", "fixed_versions": [ "v3.7.14" ], "package_name": "Traefik", "purl": "pkg:golang/Traefik" } ], "cwes": [ 295 ], "cvss_score": 7, "cvss_src": "cna_vendor", "cvss_vector": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N", "epss_score": null, "epss_percentile": null, "epss_asof": null, "automation": "deterministic", "check": true, "check_confidence_basis": "differential", "exploit": false, "pipeline_minutes": 22.060858716666665, "t0_at": null, "signals": { "check": { "at": "2026-10-08T15:00:49.034632+00:00", "days": -13.332843130856482, "is_lower_bound": true, "measured_at": "2026-10-21T23:00:06.704799+00:00", "url": null }, "trigger_signal": { "at": "2026-10-07T08:47:34+00:00", "days": -14.592044920578704, "is_lower_bound": true, "measured_at": "2026-10-21T23:00:06.704799+00:00", "url": "https://github.com/traefik/traefik/security/advisories/GHSA-cw35-4q88-3rmp" } } }
published 2026-10-08 14:38Z
last change 2026-10-21 22:34Z
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