# CVE-2026-114639: Traefik before 2.11.58 and 3.7.14 Authentication Bypass via Negotiate Connection Pool

Status: published. Published: 2026-10-22. Updated: 2026-11-04.

Traefik 2.11.0 before 2.11.58 and 3.0.0 before 3.7.14 contains an authentication bypass because a first request preauthenticated with an Authorization: Negotiate token authenticates a socket in the globally shared backend connection pool, which is never isolated. Unauthenticated attackers on separate frontend connections can be assigned that NTLM/Kerberos-bound socket and perform reads or writes with the victim's identity.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- traefik / traefik (github.com/traefik/traefik/v2): ≥ 2.11.0; < 2.11.58 (affected, semver); 2.11.58 (unaffected, semver). Source: CNA: VulnCheck
- traefik / traefik (github.com/traefik/traefik/v3): ≥ 3.0.0; < 3.7.14 (affected, semver); 3.7.14 (unaffected, semver). Source: CNA: VulnCheck

## NVD configuration conditions

Affected CPE matches depend on the following AND/OR and negation conditions:

```json
[
  {
    "negate": false,
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "2.11.58",
            "versionStartIncluding": "2.11.0",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "3.7.14",
            "versionStartIncluding": "3.0.0",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ],
    "operator": "OR"
  }
]
```

## Severity and prioritization

- CVSS 4.0: 7 (high); 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; source: CNA: VulnCheck

- CVSS 3.1: 8.7 (high); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N; source: CNA: VulnCheck

- CVSS 4.0: 7 (high); 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: disclosure@vulncheck.com

- CVSS 3.1: 8.7 (high); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N; source: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: 0.29% as of 2026-11-04; percentile 22.28%

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-287

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/traefik/traefik/security/advisories/GHSA-qm9f-w54v-q2qh (CNA: VulnCheck; vendor-advisory)

- https://www.vulncheck.com/advisories/traefik-before-2.11.58-and-3.7.14-authentication-bypass-via-negotiate-connection-pool (CNA: VulnCheck; third-party-advisory)

- https://github.com/traefik/traefik/security/advisories/GHSA-qm9f-w54v-q2qh (disclosure@vulncheck.com; Vendor Advisory)

- https://www.vulncheck.com/advisories/traefik-before-2.11.58-and-3.7.14-authentication-bypass-via-negotiate-connection-pool (disclosure@vulncheck.com; Third Party Advisory)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-114639; retrieved 2026-11-04; source updated 2026-11-04

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-114639; retrieved 2026-11-04; source updated 2026-11-04

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-114639; retrieved 2026-11-04; source updated Not reported

Revision: 905cf9cd734b61a3afe972790d31f5ca395a2212b4982284b2e3ed68b4454164

Canonical: https://y2.dev/cve/CVE-2026-114639

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.