Contour: Lua code injection via Cookie Path Rewrite Policy
Summary
| CVE | CVE-2026-41246 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-23 19:17:29 UTC |
| Updated | 2026-04-23 19:17:29 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 8.1 HIGH from [email protected]
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Problem Types: CWE-94 | CWE-94 CWE-94: Improper Control of Generation of Code ('Code Injection')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 8.1 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H |
| 3.1 | CNA | DECLARED | 8.1 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
NoneAvailability
HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Projectcontour | Contour | affected >= 1.33.0, < 1.33.4 | Not specified |
| CNA | Projectcontour | Contour | affected >= 1.32.0, < 1.32.5 | Not specified |
| CNA | Projectcontour | Contour | affected >= 1.19.0, < 1.31.6 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/projectcontour/contour/releases/tag/v1.32.5 | [email protected] | github.com | |
| github.com/projectcontour/contour/security/advisories/GHSA-x4mj-7f9g-29h4 | [email protected] | github.com | |
| github.com/projectcontour/contour/releases/tag/v1.33.4 | [email protected] | github.com | |
| github.com/projectcontour/contour/releases/tag/v1.31.6 | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.