Vulnerability-Lookup

CVE-2026-50149 (GCVE-0-2026-50149)

Vulnerability from cvelistv5 – Published: 2026-08-19 14:16 – Updated: 2026-08-25 02:03

Title

Contour has Improper JWT Verification for Non-SNI Requests on Virtual Hosts with Fallback Certificate Enabled

Summary

Contour is a Kubernetes ingress controller using Envoy proxy. In versions 1.23.0 through 1.33.4, when an `HTTPProxy` is configured with incompatible combination of both `.spec.virtualhost.tls.enableFallbackCertificate: true` and `.spec.virtualhost.jwtProviders`, Contour does not reject the configuration. Consequently, requests from clients that do not send TLS SNI or send an unrecognized SNI (one that does not match any `HTTPProxy` FQDN) bypass configured JWT verification and are proxied to upstream services without a valid token. This issue is fixed in Contour v1.33.5. Contour now rejects and marks invalid any `HTTPProxy` resources that combine `.spec.virtualhost.tls.enableFallbackCertificate: true` with `.spec.virtualhost.jwtProviders`. Affected resources will receive a status condition with the error reason `TLSIncompatibleFeatures`. As a workaround, do not enable `.spec.virtualhost.tls.enableFallbackCertificate` on `HTTPProxy` resources that also define `.spec.virtualhost.jwtProviders`. Remove one of the two settings to avoid the invalid configuration.

Severity

6.5 (Medium)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-25 02:03 UTC

CWE

CWE-295 - Improper Certificate Validation

Assigner

GitHub_M mitre root Scorecard

References

1 reference

URL	Tags
https://github.com/projectcontour/contour/securit…	x_refsource_CONFIRM

Impacted products

1 product

Vendor	Product	Version
projectcontour	contour	Affected: >= 1.23.0, < 1.33.5

Show details on NVD website

JSON

To clipboard

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      "title": "github.com/projectcontour/contour: Contour: JWT verification bypass allows unauthorized access via HTTPProxy misconfiguration",
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}

bit-contour-2026-50149

Vulnerability from bitnami_vulndb

Published

2026-08-25 08:38

Modified

2026-08-25 09:03

Summary

Contour has Improper JWT Verification for Non-SNI Requests on Virtual Hosts with Fallback Certificate Enabled

Details

Contour is a Kubernetes ingress controller using Envoy proxy. In versions 1.23.0 through 1.33.4, when an HTTPProxy is configured with incompatible combination of both .spec.virtualhost.tls.enableFallbackCertificate: true and .spec.virtualhost.jwtProviders, Contour does not reject the configuration. Consequently, requests from clients that do not send TLS SNI or send an unrecognized SNI (one that does not match any HTTPProxy FQDN) bypass configured JWT verification and are proxied to upstream services without a valid token. This issue is fixed in Contour v1.33.5. Contour now rejects and marks invalid any HTTPProxy resources that combine .spec.virtualhost.tls.enableFallbackCertificate: true with .spec.virtualhost.jwtProviders. Affected resources will receive a status condition with the error reason TLSIncompatibleFeatures. As a workaround, do not enable .spec.virtualhost.tls.enableFallbackCertificate on HTTPProxy resources that also define .spec.virtualhost.jwtProviders. Remove one of the two settings to avoid the invalid configuration.

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "contour",
        "purl": "pkg:bitnami/contour"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.23.0"
            },
            {
              "fixed": "1.33.5"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N",
          "type": "CVSS_V3"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-50149"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:projectcontour:contour:*:*:*:*:*:kubernetes:*:*"
    ],
    "severity": "Medium"
  },
  "details": "Contour is a Kubernetes ingress controller using Envoy proxy. In versions 1.23.0 through 1.33.4, when an `HTTPProxy` is configured with incompatible combination of both `.spec.virtualhost.tls.enableFallbackCertificate: true` and `.spec.virtualhost.jwtProviders`, Contour does not reject the configuration. Consequently, requests from clients that do not send TLS SNI or send an unrecognized SNI (one that does not match any `HTTPProxy` FQDN) bypass configured JWT verification and are proxied to upstream services without a valid token. This issue is fixed in Contour v1.33.5. Contour now rejects and marks invalid any `HTTPProxy` resources that combine `.spec.virtualhost.tls.enableFallbackCertificate: true` with `.spec.virtualhost.jwtProviders`. Affected resources will receive a status  condition with the error reason `TLSIncompatibleFeatures`. As a workaround, do not enable `.spec.virtualhost.tls.enableFallbackCertificate` on `HTTPProxy` resources that also define `.spec.virtualhost.jwtProviders`. Remove one of the two settings to avoid the invalid configuration.",
  "id": "BIT-contour-2026-50149",
  "modified": "2026-08-25T09:03:39.364Z",
  "published": "2026-08-25T08:38:13.920Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/projectcontour/contour/security/advisories/GHSA-g3xr-5w5j-w4q4"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50149"
    }
  ],
  "schema_version": "1.6.2",
  "summary": "Contour has Improper JWT Verification for Non-SNI Requests on Virtual Hosts with Fallback Certificate Enabled"
}

CLEANSTART-2026-CU86688 (CVE-2026-50149)

Vulnerability from cleanstart – Published: 2026-09-19 00:37 – Updated: 2026-09-18 14:08 – Source website

Summary

Contour is a Kubernetes ingress controller using Envoy proxy

Details

Security vulnerability affects the external-dns package. Contour is a Kubernetes ingress controller using Envoy proxy.

Severity

9.8 (Critical)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

URL

Type

	https://github.com/cleanstart-dev/cleanstart-secu…	ADVISORY
	https://osv.dev/vulnerability/CVE-2026-50149	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-50149	WEB

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "CleanStart",
        "name": "external-dns"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.20.0-r2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "credits": [],
  "database_specific": {},
  "details": "Security vulnerability affects the external-dns package. Contour is a Kubernetes ingress controller using Envoy proxy.",
  "id": "CLEANSTART-2026-CU86688",
  "modified": "2026-09-18T14:08:41Z",
  "published": "2026-09-19T00:37:05.838798Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/cleanstart-dev/cleanstart-security-advisories/tree/main/advisories/2026/CLEANSTART-2026-CU86688.json"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/CVE-2026-50149"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50149"
    }
  ],
  "related": [],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Contour is a Kubernetes ingress controller using Envoy proxy",
  "upstream": [
    "CVE-2026-50149"
  ]
}

EUVD-2026-358406

European Vulnerability Database identifier assigned by ENISA

Reserved

2026-10-02 08:29

Assigner

ENISA

Alias of

a CVE record, shown under related vulnerabilities. This identifier carries no description, severity or references of its own: they belong to that CVE.

JSON

To clipboard

{
  "assigner": "ENISA",
  "date_reserved": "2026-10-02T08:29:49.868567+00:00",
  "id": "EUVD-2026-358406"
}

FKIE_CVE-2026-50149

Vulnerability from fkie_nvd - Published: 2026-08-19 15:17 - Updated: 2026-09-18 20:09

Severity

6.5 (Medium) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/projectcontour/contour/security/advisories/GHSA-g3xr-5w5j-w4q4

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "contour",
          "vendor": "projectcontour",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 1.23.0, \u003c 1.33.5"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Contour is a Kubernetes ingress controller using Envoy proxy. In versions 1.23.0 through 1.33.4, when an `HTTPProxy` is configured with incompatible combination of both `.spec.virtualhost.tls.enableFallbackCertificate: true` and `.spec.virtualhost.jwtProviders`, Contour does not reject the configuration. Consequently, requests from clients that do not send TLS SNI or send an unrecognized SNI (one that does not match any `HTTPProxy` FQDN) bypass configured JWT verification and are proxied to upstream services without a valid token. This issue is fixed in Contour v1.33.5. Contour now rejects and marks invalid any `HTTPProxy` resources that combine `.spec.virtualhost.tls.enableFallbackCertificate: true` with `.spec.virtualhost.jwtProviders`. Affected resources will receive a status  condition with the error reason `TLSIncompatibleFeatures`. As a workaround, do not enable `.spec.virtualhost.tls.enableFallbackCertificate` on `HTTPProxy` resources that also define `.spec.virtualhost.jwtProviders`. Remove one of the two settings to avoid the invalid configuration."
    }
  ],
  "id": "CVE-2026-50149",
  "lastModified": "2026-09-18T20:09:01.757",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 4.2,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-50149",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-08-25T02:03:02.855901Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-19T15:17:08.710",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/projectcontour/contour/security/advisories/GHSA-g3xr-5w5j-w4q4"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-295"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}

GHSA-G3XR-5W5J-W4Q4

Vulnerability from github – Published: 2026-07-02 17:15 – Updated: 2026-07-02 17:15

Summary

Contour has Improper JWT Verification for Non-SNI Requests on Virtual Hosts with Fallback Certificate Enabled

Details

Impact

When an HTTPProxy is configured with incompatible combination of both .spec.virtualhost.tls.enableFallbackCertificate: true and .spec.virtualhost.jwtProviders, Contour does not reject the configuration. Consequently, requests from clients that do not send TLS SNI or send an unrecognized SNI (one that does not match any HTTPProxy FQDN) bypass configured JWT verification and are proxied to upstream services without a valid token.

To list all HTTPProxies with this invalid configuration, run

kubectl get httpproxies -A -o json | jq -r '
  .items[]
  | select(.spec.virtualhost | .tls.enableFallbackCertificate and .jwtProviders)
  | "Invalid HTTPProxy found: \(.metadata.namespace)/\(.metadata.name)"
'

Patches

This issue is fixed in Contour v1.33.5. Contour now rejects and marks invalid any HTTPProxy resources that combine .spec.virtualhost.tls.enableFallbackCertificate: true with .spec.virtualhost.jwtProviders. Affected resources will receive a status condition with the error reason TLSIncompatibleFeatures.

Workarounds

Do not enable .spec.virtualhost.tls.enableFallbackCertificate on HTTPProxy resources that also define .spec.virtualhost.jwtProviders. Remove one of the two settings to avoid the invalid configuration.

References

Contour fallback certificate documentation: https://projectcontour.io/docs/main/config/tls-termination/#fallback-certificate
Contour JWT verification documentation: https://projectcontour.io/docs/main/config/jwt-verification/

Severity

6.5 (Medium)


                  
                    CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/projectcontour/contour"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.23.0"
            },
            {
              "fixed": "1.33.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-50149"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-295"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-02T17:15:20Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nWhen an `HTTPProxy` is configured with incompatible combination of both `.spec.virtualhost.tls.enableFallbackCertificate: true` and `.spec.virtualhost.jwtProviders`, Contour does not reject the configuration. Consequently, requests from clients that do not send TLS SNI or send an unrecognized SNI (one that does not match any `HTTPProxy` FQDN) bypass configured JWT verification and are proxied to upstream services without a valid token.\n\nTo list all `HTTPProxies` with this invalid configuration, run\n\n```bash\nkubectl get httpproxies -A -o json | jq -r \u0027\n  .items[]\n  | select(.spec.virtualhost | .tls.enableFallbackCertificate and .jwtProviders)\n  | \"Invalid HTTPProxy found: \\(.metadata.namespace)/\\(.metadata.name)\"\n\u0027\n```\n\n### Patches\n\nThis issue is fixed in Contour v1.33.5. Contour now rejects and marks invalid any `HTTPProxy` resources that combine `.spec.virtualhost.tls.enableFallbackCertificate: true` with `.spec.virtualhost.jwtProviders`. Affected resources will receive a status  condition with the error reason `TLSIncompatibleFeatures`.\n\n### Workarounds\n\nDo not enable `.spec.virtualhost.tls.enableFallbackCertificate` on `HTTPProxy` resources that also define `.spec.virtualhost.jwtProviders`. Remove one of the two settings to avoid the invalid configuration.\n\n### References\n\n- Contour fallback certificate documentation: https://projectcontour.io/docs/main/config/tls-termination/#fallback-certificate\n- Contour JWT verification documentation: https://projectcontour.io/docs/main/config/jwt-verification/",
  "id": "GHSA-g3xr-5w5j-w4q4",
  "modified": "2026-07-02T17:15:20Z",
  "published": "2026-07-02T17:15:20Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/projectcontour/contour/security/advisories/GHSA-g3xr-5w5j-w4q4"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/projectcontour/contour"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Contour has Improper JWT Verification for Non-SNI Requests on Virtual Hosts with Fallback Certificate Enabled"
}

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.

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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