github.com/projectcontour/contour

CVE-2026-41246

CVE-2026-41246 is a high-severity code injection vulnerability in github.com/projectcontour/contour (go), affecting versions >= 1.19.0, < 1.31.6. It is fixed in 1.31.6, 1.32.5, 1.33.4.

Key facts
CVSS score
8.1
High
Attack vector
Network
Issuing authority
GitHub Advisory Database
Affected package
github.com/projectcontour/contour
Fixed in
1.31.6, 1.32.5, 1.33.4
Disclosed
2026

Summary

Impact 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 the following fields that results in arbitrary code execution in the Envoy proxy: spec.routes[].cookieRewritePolicies[].pathRewrite.value spec.routes[].services[].cookieRewritePolicies[].pathRewrite.value 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, which could be used to read all Contour xDS configuration, including TLS certificates and private keys of other tenants. Cause denial of service for other tenants sharing the Envoy instance. Other use cases of Lua filter are not vulnerable. Patches The fix is available in Contour v1.33.4, v1.32.5, and v1.31.6. v1.33.4: User-provided values are no longer interpolated into Lua code. Use of text/template is removed. Requires Envoy 1.35.0 or later. v1.32.5, v1.31.6: User-provided values are escaped before interpolation into Lua code. Workarounds There are no workarounds. Users should upgrade to a patched version.

Impact

What is code injection?

Untrusted input is evaluated as executable code within the application's runtime environment. Typical impact: arbitrary code execution within the application's privilege context.

Severity and exposure

CVE-2026-41246 has a CVSS score of 8.1 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.

A fixed version is available (1.31.6, 1.32.5, 1.33.4). Upgrading removes the vulnerable code path.

Affected versions

go

  • github.com/projectcontour/contour (>= 1.19.0, < 1.31.6)
  • github.com/projectcontour/contour (>= 1.32.0, < 1.32.5)
  • github.com/projectcontour/contour (>= 1.33.0, < 1.33.4)

Security releases

  • github.com/projectcontour/contour → 1.31.6 (go)
  • github.com/projectcontour/contour → 1.32.5 (go)
  • github.com/projectcontour/contour → 1.33.4 (go)
Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.

Kodem's Application Detection and Response identifies whether CVE-2026-41246 is reachable in your applications. Explore runtime application protection for your team.

See if CVE-2026-41246 is reachable in your applications. Get a demo

Already deployed Kodem? See CVE-2026-41246 in your environment

Remediation advice

Upgrade the following packages to resolve this vulnerability:

  • Upgrade github.com/projectcontour/contour to 1.31.6 or later
  • Upgrade github.com/projectcontour/contour to 1.32.5 or later
  • Upgrade github.com/projectcontour/contour to 1.33.4 or later

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently asked questions about CVE-2026-41246

What is CVE-2026-41246?

CVE-2026-41246 is a high-severity code injection vulnerability in github.com/projectcontour/contour (go), affecting versions >= 1.19.0, < 1.31.6. It is fixed in 1.31.6, 1.32.5, 1.33.4. Untrusted input is evaluated as executable code within the application's runtime environment.

How severe is CVE-2026-41246?

CVE-2026-41246 has a CVSS score of 8.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Which versions of github.com/projectcontour/contour are affected by CVE-2026-41246?

github.com/projectcontour/contour (go) versions >= 1.19.0, < 1.31.6 is affected.

Is there a fix for CVE-2026-41246?

Yes. CVE-2026-41246 is fixed in 1.31.6, 1.32.5, 1.33.4. Upgrade to this version or later.

Is CVE-2026-41246 exploitable, and should I be worried?

Whether CVE-2026-41246 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo

What actually determines whether CVE-2026-41246 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

How do I fix CVE-2026-41246?
  • Upgrade github.com/projectcontour/contour to 1.31.6 or later
  • Upgrade github.com/projectcontour/contour to 1.32.5 or later
  • Upgrade github.com/projectcontour/contour to 1.33.4 or later

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