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Fencer Vulns
medium 6.5

CVE-2026-50149 json

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

published 2026-07-02 4 mo ago modified 2026-09-18 51 d ago also BIT-contour-2026-50149 , EUVD-2026-62414 , GHSA-g3xr-5w5j-w4q4 , GO-2026-5889

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 8%
public exploits
0
none known

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.

Patch / fix

  • go github.com/projectcontour/contour 1.33.5
  • bitnami contour 1.33.5
  • projectcontour contour 1.33.5
  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1

opensuse advisories openSUSE-SU-2026:21483-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-50149 updated cvss 6.5

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

  • Red Hat ExternalDNS Operator edo/external-dns-rhel8, edo/external-dns-rhel9
    affected: workaround, no fix available, no fix planned “Upgrade to Contour v1.33.5 or later. As a workaround, do not enable enableFallbackCertificate on HTTPProxy resources that also define jwtProviders.”
  • Red Hat OpenShift Container Platform 4 openshift4/ose-contour-rhel8
    affected: workaround, no fix available “Upgrade to Contour v1.33.5 or later. As a workaround, do not enable enableFallbackCertificate on HTTPProxy resources that also define jwtProviders.”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 8% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
GitHub 3.1 6.5 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
OSV 3.1 6.5 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N

Affected packages

ecosystem package affected fixed in
go github.com/projectcontour/contour
>=1.23.0, <1.33.5
1.33.5
bitnami contour
>=1.23.0, <1.33.5
1.33.5

Affected products

  • projectcontour contour

Classification

Weakness
  • CWE-295 Improper Certificate Validation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.