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.

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euvd · EUVD-2026-62414

Published

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nvd · CVE-2026-50149

Published

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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/

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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

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Affected versions, risk and source history

Exploitation and risk

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cve-program · CVE-2026-50149

Published

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

Source published: 19 Aug 2026 14:16:21 UTC
Source modified: 25 Aug 2026 02:03:11 UTC
Saved here: 23 Oct 2026 15:48:27 UTC
Source terms: CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

Source: cve-program · CVE Program Terms of Use. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.

CVSS 3.1 · 6.5 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N

euvd · EUVD-2026-62414

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.virt…

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EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.

Original publisher date fields

datePublished: Aug 19, 2026, 2:16:21 PM

dateUpdated: Aug 25, 2026, 2:03:11 AM

Source published: Aug 19, 2026, 2:16:21 PM (timezone not stated)
Source modified: Aug 25, 2026, 2:03:11 AM (timezone not stated)
Saved here: 11 Nov 2026 13:05:56 UTC
Source terms: ENISA EUVD · source terms and attribution apply

Original source record · Cite this exact observation · Complete original publisher JSON

Source: euvd · ENISA EUVD · source terms and attribution apply. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.

EUVD CVSS 3.1 · 6.5 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N

nvd · 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.virt…

Additional publisher context

NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.

Source analysis status: Deferred

Weakness classifications: CWE-295

Original publisher date fields

published: 2026-08-19T15:17:08.710

lastModified: 2026-09-18T20:09:01.757

Source published: 19 Aug 2026 15:17:08 UTC
Source modified: 18 Sep 2026 20:09:01 UTC
Saved here: 25 Oct 2026 12:17:38 UTC
Source terms: NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

Source: nvd · NIST NVD usage terms; underlying source attribution retained. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.

CVSS 3.1 · [email protected] · Secondary · 6.5 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N

osv · GHSA-g3xr-5w5j-w4q4

Published

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

Source published: 2 Jul 2026 17:15:20 UTC
Source modified: 10 Sep 2026 03:50:51 UTC
Saved here: 24 Oct 2026 13:19:41 UTC
Source terms: GitHub Advisory Database · CC-BY-4.0

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CVSS_V3 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N

Publisher rating · MODERATE

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

Source published: 7 Jul 2026 15:26:37 UTC
Source modified: 26 Aug 2026 01:11:36 UTC
Saved here: 24 Oct 2026 13:19:41 UTC
Source terms: OSV · upstream source license applies

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