CVE-2026-41246

HIGH EPSS 35.3%
Published Apr 23, 20262mo ago · Modified Jun 17, 20261w ago
8.1 CVSS 3.1
High
Find Similar
Published Apr 23, 2026 2mo ago
Last Modified Jun 17, 2026 1w ago

Description

Contour is a Kubernetes ingress controller using Envoy proxy. From v1.19.0 to before v1.33.4, v1.32.5, and v1.31.6, Contour's Cookie Rewriting feature is vulnerable to Lua code injection. An attacker with RBAC permissions to create or modify HTTPProxy resources can craft a malicious value in spec.routes[].cookieRewritePolicies[].pathRewrite.value or spec.routes[].services[].cookieRewritePolicies[].pathRewrite.value that results in arbitrary code execution in the Envoy proxy. The cookie rewriting feature is internally implemented using Envoy's HTTP Lua filter. User-controlled values are interpolated into Lua source code using Go text/template without sufficient sanitization. The injected code only executes when processing traffic on the attacker's own route, which they already control. However, since Envoy runs as shared infrastructure, the injected code can also read Envoy's xDS client credentials from the filesystem or cause denial of service for other tenants sharing the Envoy instance. This vulnerability is fixed in v1.33.4, v1.32.5, and v1.31.6.

CVSS Details

Base Score
8.1
Exploitability
2.8
Impact
5.2
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality High
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
35.3% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-94 Improper Control of Generation of Code (Code Injection) Injection

Affected Products 3

VendorProductVersionRange
projectcontourcontour*≥1.19.0  –  <1.31.6
projectcontourcontour*≥1.32.0  –  <1.32.5
projectcontourcontour*≥1.33.0  –  <1.33.4

References 4

  • github.com https://github.com/projectcontour/contour/releases/tag/v1.31.6
    Release Notes
  • github.com https://github.com/projectcontour/contour/releases/tag/v1.32.5
    Release Notes
  • github.com https://github.com/projectcontour/contour/releases/tag/v1.33.4
    Release Notes
  • github.com https://github.com/projectcontour/contour/security/advisories/GHSA-x4mj-7f9g-29h4
    PatchVendor Advisory

Remediation

  • github.com https://github.com/projectcontour/contour/security/advisories/GHSA-x4mj-7f9g-29h4
    PatchVendor Advisory