CVE-2026-41246
Description
A flaw was found in Contour, a Kubernetes ingress controller. An attacker with Role-Based Access Control (RBAC) permissions to manage HTTPProxy resources can exploit a Lua code injection vulnerability within Contour's Cookie Rewriting feature. By crafting a malicious value in specific configuration fields, the attacker can achieve arbitrary code execution in the Envoy proxy. This could allow them to read sensitive credentials from the filesystem or cause a denial of service for other users sharing the Envoy instance.
Statement
This is an Important vulnerability in Contour's Cookie Rewriting feature, allowing arbitrary code execution and denial of service. An attacker with Role-Based Access Control (RBAC) permissions to create or modify HTTPProxy resources can inject malicious Lua code into the Envoy proxy. This could lead to unauthorized access to sensitive credentials or disrupt services for other tenants sharing the Envoy instance.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.1 | N/A | 8.1 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism
In some cases, injectable code controls authentication; this may lead to a remote vulnerability.
Access Control
Technical Impact: Gain Privileges or Assume Identity
Injected code can access resources that the attacker is directly prevented from accessing.
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
When a product allows a user's input to contain code syntax, it might be possible for an attacker to craft the code in such a way that it will alter the intended control flow of the product. As a result, code injection can often result in the execution of arbitrary code. Code injection attacks can also lead to loss of data integrity in nearly all cases, since the control-plane data injected is always incidental to data recall or writing.
Non-Repudiation
Technical Impact: Hide Activities
Often the actions performed by injected control code are unlogged.
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