Vulnerability-Lookup

GHSA-RGPG-CPWG-4F45

Vulnerability from github – Published: 2026-09-04 12:31 – Updated: 2026-09-04 12:31

Details

Traefik versions >= v3.7.0 and <= v3.7.10 contain an authentication bypass in the Kubernetes Ingress NGINX provider. The TLS option generated for an Ingress carrying the nginx.ingress.kubernetes.io/auth-tls-secret annotation was named after the Ingress namespace and name. As a result, two Ingress objects sharing the same host, the same client CA secret, and the same client-authentication mode produced two distinct TLS option names for that host. Traefik treats this as a TLS options conflict and falls back to the entry point's default TLS configuration, which does not request a client certificate, so a route configured with nginx.ingress.kubernetes.io/auth-tls-verify-client: "on" becomes reachable without a client certificate. Only the v3.7 line is affected; the issue is fixed in v3.7.11.

Severity

8.2 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-85596"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-287"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-04T12:17:23Z",
    "severity": "HIGH"
  },
  "details": "Traefik versions \u003e= v3.7.0 and \u003c= v3.7.10 contain an authentication bypass in the Kubernetes Ingress NGINX provider. The TLS option generated for an Ingress carrying the nginx.ingress.kubernetes.io/auth-tls-secret annotation was named after the Ingress namespace and name. As a result, two Ingress objects sharing the same host, the same client CA secret, and the same client-authentication mode produced two distinct TLS option names for that host. Traefik treats this as a TLS options conflict and falls back to the entry point\u0027s default TLS configuration, which does not request a client certificate, so a route configured with nginx.ingress.kubernetes.io/auth-tls-verify-client: \"on\" becomes reachable without a client certificate. Only the v3.7 line is affected; the issue is fixed in v3.7.11.",
  "id": "GHSA-rgpg-cpwg-4f45",
  "modified": "2026-09-04T12:31:00Z",
  "published": "2026-09-04T12:31:00Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/traefik/traefik/security/advisories/GHSA-j994-9gqj-9hwq"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-85596"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/traefik-3.7-authentication-bypass-via-tls-option-conflict"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/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",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-85596 (GCVE-0-2026-85596)

Vulnerability from cvelistv5 – Published: 2026-09-04 11:30 – Updated: 2026-09-04 11:30

Title

Traefik v3.7 Authentication Bypass via TLS Option Conflict

Summary

Severity

8.2 (High)


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

CWE

CWE-287 - Improper Authentication

Assigner

VulnCheck mitre root

References

2 references

URL	Tags
https://github.com/traefik/traefik/security/advis…	vendor-advisory
https://www.vulncheck.com/advisories/traefik-3.7-…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
traefik	traefik	Affected: 3.7.0 , ≤ 3.7.12 (semver) cpe:2.3:a:traefik:traefik::::::::

Date Public

2026-08-21 00:00

Credits

james-yusuke

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:golang/Traefik",
          "product": "traefik",
          "vendor": "traefik",
          "versions": [
            {
              "lessThanOrEqual": "3.7.12",
              "status": "affected",
              "version": "3.7.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*",
                  "versionEndIncluding": "3.7.12",
                  "versionStartIncluding": "3.7.0",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "james-yusuke"
        }
      ],
      "datePublic": "2026-08-21T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "Traefik versions \u003e= v3.7.0 and \u003c= v3.7.10 contain an authentication bypass in the Kubernetes Ingress NGINX provider. The TLS option generated for an Ingress carrying the nginx.ingress.kubernetes.io/auth-tls-secret annotation was named after the Ingress namespace and name. As a result, two Ingress objects sharing the same host, the same client CA secret, and the same client-authentication mode produced two distinct TLS option names for that host. Traefik treats this as a TLS options conflict and falls back to the entry point\u0027s default TLS configuration, which does not request a client certificate, so a route configured with nginx.ingress.kubernetes.io/auth-tls-verify-client: \"on\" becomes reachable without a client certificate. Only the v3.7 line is affected; the issue is fixed in v3.7.11."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 8.2,
            "baseSeverity": "HIGH",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "NONE"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-287",
              "description": "Improper Authentication",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-04T11:30:00.112Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "GitHub Security Advisory (GHSA-j994-9gqj-9hwq)",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://github.com/traefik/traefik/security/advisories/GHSA-j994-9gqj-9hwq"
        },
        {
          "name": "VulnCheck Advisory: Traefik v3.7 Authentication Bypass via TLS Option Conflict",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/traefik-3.7-authentication-bypass-via-tls-option-conflict"
        }
      ],
      "title": "Traefik v3.7 Authentication Bypass via TLS Option Conflict",
      "x_generator": {
        "engine": "vulncheck-endgame"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-85596",
    "datePublished": "2026-09-04T11:30:00.112Z",
    "dateReserved": "2026-09-04T10:59:00.162Z",
    "dateUpdated": "2026-09-04T11:30:00.112Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

GHSA-RGPG-CPWG-4F45

CVE-2026-85596 (GCVE-0-2026-85596)

Tags

Sightings

Nomenclature