CVE-2026-50149: Github.com/projectcontour/contour Contour Has Improper JWT Verification Vulnerability
MODERATECVE-2026-50149 is a MODERATE (CVSS 6.5) contour has improper jwt verification vulnerability (CWE-295: Improper Certificate Validation) affecting Github.com/projectcontour/contour libraries in the Go ecosystem. The issue involves contour has improper jwt verification for non-sni requests on virtual hosts with fallback certificate enabled. Remediation is available by upgrading affected packages to version 1.33.5.
CVE-2026-50149 at a Glance
Security Impact
CVSS: 6.5
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N).
How to Fix CVE-2026-50149
To remediate this vulnerability, upgrade all affected Github.com/projectcontour/contour dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade github.com/projectcontour/contour to 1.33.5Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for github.com/projectcontour/contourHow to Check if You Are Affected
To determine whether your application is affected by CVE-2026-50149, inspect your project dependencies for Github.com/projectcontour/contour:
inspect dependencies for github.com/projectcontour/contourAnalyze the terminal output to locate any version of Github.com/projectcontour/contour in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.33.5), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-295: Improper Certificate Validation, where the product does not validate, or incorrectly validates, a certificate. In Github.com/projectcontour/contour, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-50149 Affected Github.com/projectcontour/contour Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
github.com/projectcontour/contour
|
Go |
≥ 1.23.0
< 1.33.5
|
1.33.5
|
References
Frequently Asked Questions
What is CVE-2026-50149?
Which Github.com/projectcontour/contour versions are affected?
What version fixes CVE-2026-50149?
Is github.com/projectcontour/contour affected?
What is the CVSS score of CVE-2026-50149?
What CWE is associated with CVE-2026-50149?
How can I check Go dependencies for CVE-2026-50149?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-g3xr-5w5j-w4q4",
"modified" : "2026-07-02T17:15:20Z",
"published" : "2026-07-02T17:15:20Z",
"aliases" : [ "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/",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/projectcontour/contour"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "1.23.0"
}, {
"fixed" : "1.33.5"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/projectcontour/contour/security/advisories/GHSA-g3xr-5w5j-w4q4"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/projectcontour/contour"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-295" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2026-07-02T17:15:20Z",
"nvd_published_at" : null
}
}