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OpenAdvisories
Medium · 6.5 CVE-2026-50149 BIT-contour-2026-50149EUVD-2026-62414GHSA-g3xr-5w5j-w4q4GO-2026-5889

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

Published Aug 19, 2026 · Updated Aug 25, 2026 · Assigned by GitHub_M

Description

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.

Affected products

VendorProductAffectedFixed
projectcontour contour >= 1.23.0, < 1.33.5 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260723T184607-160000.1.1 openSUSE-SU-2026:21483-1

Wolfi

ReleasePackageFixed inAdvisory
Wolfi rolling external-dns-0.21 0.21.0-r11 —

Affected packages

EcosystemPackageAffectedFixedRecord
Go github.com/projectcontour/contour >= 1.23.0, < 1.33.5 1.33.5 GHSA-g3xr-5w5j-w4q4

Advisories 1

References