{"id":"CVE-2026-50149","aliases":["BIT-contour-2026-50149","GHSA-g3xr-5w5j-w4q4","GO-2026-5889"],"url":"https://o3.security/vulnerability/CVE-2026-50149","summary":"Contour has Improper JWT Verification for Non-SNI Requests on Virtual Hosts with Fallback Certificate Enabled","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 '\n  .items[]\n  | select(.spec.virtualhost | .tls.enableFallbackCertificate and .jwtProviders)\n  | \"Invalid HTTPProxy found: \\(.metadata.namespace)/\\(.metadata.name)\"\n'\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/","published":"2026-08-19T14:16:21.476Z","modified":"2026-10-21T02:58:24.697498263Z","cvss":{"score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N"},"epss":{"score":0.00147,"percentile":0.04272,"asOf":"2026-09-12"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/projectcontour/contour","fixedVersion":"1.33.5"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50149.json"},{"type":"ADVISORY","url":"https://github.com/projectcontour/contour/security/advisories/GHSA-g3xr-5w5j-w4q4"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-50149"},{"type":"PACKAGE","url":"https://github.com/projectcontour/contour"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-21T02:58:24.697498263Z"}}