Sign in Sign up
JA · EN · FR
SecPulse
Categories
CVE-2026-41246 high CVSS 8.1

Code Injection in github.com/projectcontour/contour (CVE-2026-41246)

Summary

Code injection in github.com/projectcontour/contour (CVE-2026-41246). Confidential information can be exposed externally. Mitigation: upgrade to 1.33.4 or later.

Original description

The description as published by the source.

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.

Source: GitHub Security Advisories (Global) NVD GitHub Advisory

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2026-41246 has been found in github.com/projectcontour/contour.
Confidential information can be exposed externally. CVSS score: 8.1/10.
What to do: upgrade github.com/projectcontour/contour to 1.33.4 or later.
If unsure, ask your IT team or search "github.com/projectcontour/contour CVE-2026-41246" on the vendor's site.

CVE-2026-41246 (github.com/projectcontour/contour) — CWE-94 / CVSS v3 8.1
Attack vector: remote (network-reachable) / no user interaction
Patched: 1.33.4 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

Arbitrary code execution (CWE-94) exists in github.com/projectcontour/contour.

📍 Affected scope

Check the vendor advisory for the affected versions of github.com/projectcontour/contour.

🔥 Severity

Severity: High (CVSS 8.1/10). Confidential information can be exposed externally.

🔧 How to fix

Update to 1.33.4.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'github.com/projectcontour/contour' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

  1. 1
    Identify exposure identify 
    grep -r 'github.com/projectcontour/contour' . | grep -v node_modules

    リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で github.com/projectcontour/contour を grep し、稼働しているサービス・バージョンを把握する。

  2. 2
    Apply patch patch 
    Upgrade github.com/projectcontour/contour to 1.33.4

    ステージング環境で 1.33.4 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。

  3. 3
    Post-deployment verification verify 
    Confirm patched version is live in production

    パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

go github.com/projectcontour/contour
[{"type":"SEMVER","events":[{"introduced":"1.33.0"},{"fixed":"1.33.4"}]}]
Bitnami contour
[{"type":"SEMVER","events":[{"introduced":"1.19.0"},{"fixed":"1.31.6"},{"introduced":"1.32.0"},{"fixed":"1.32.5"},{"introduced":"1.33.0"},{"fixed":"1.33.4"}]}]

References

We use cookies for analytics and ad measurement. This setting applies to all Game co., Ltd. sites. Details