CVE-2026-50149

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

CVSS 3.1 6.5 MEDIUMEUVD CVSS 3.1 6.5 CVSS 3.1 · [email protected] · Secondary 6.5 MEDIUMCVSS_V3 Publisher rating MODERATEFixed by github.com/projectcontour/contour 1.33.5osv · severity unknownFixed by github.com/projectcontour/contour 1.33.5KEV status unknown

Original advisory

cve-program · CVE-2026-50149

Published

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.

Read the publisher's advisory

euvd · EUVD-2026-62414

Published

Read the publisher's advisory

nvd · CVE-2026-50149

Published

Read the publisher's advisory

osv · GHSA-g3xr-5w5j-w4q4

Published

### 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 ```bash 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/

Read the publisher's advisory

osv · GO-2026-5889

Published

Contour has Improper JWT Verification for Non-SNI Requests on Virtual Hosts with Fallback Certificate Enabled in github.com/projectcontour/contour

Read the publisher's advisory

Affected versions, risk and source history

Exploitation and risk

Source status

CISA KEV lists vulnerabilities known to be exploited. FIRST EPSS estimates the likelihood of exploitation in the next 30 days. An unavailable score does not mean zero risk.

Which CVEs have scores here?

This view includes predictions for CVE identifiers explicitly listed in public NuGet advisories. Microsoft release pages have their own prediction coverage. Check source status for the scope and latest checks.

No exploitation or prediction data is available here for these CVEs. This does not mean they are safe or unlikely to be exploited.

Risk history

Compare earlier KEV listings and daily EPSS scores. Advisory wording and affected versions have a separate history.

When does an EPSS score appear as a change?

A prediction change is reported when EPSS rises from below 10% to 10% or higher. Other daily score changes remain in this history.

Advisory history

12 saved versions

See how the publisher's advisory changed over time. Each link opens the version saved at that time. The publisher's update date can differ from the date shown here.

How advisory history works

Each link identifies one complete publisher record. History can include advisories that previously shared an identifier; an identifier removed by a publisher no longer establishes a current relationship. A historical link shows only that record and earlier saved versions. Failed checks and unchanged reads do not create new versions.

11 Nov 2026 13:05:56 UTC