CVE-2026-67309
Description
A flaw was found in Traefik. This path traversal vulnerability exists in the Kubernetes Ingress NGINX provider's RewriteTarget middleware. A remote attacker can craft a special request that uses dot-segment traversal to bypass authentication mechanisms like BasicAuth, DigestAuth, or ForwardAuth. This allows access to otherwise protected administrative endpoints.
Statement
A flaw was found in Traefik's Kubernetes Ingress NGINX provider RewriteTarget middleware (v3.7.0 through v3.7.7) where captured un-delimited regex segments are rewritten without post-replacement path normalization validation. In Kubernetes environments utilizing Traefik, a remote unauthenticated attacker can supply dot-segment traversal sequences in Ingress paths (e.g., /api../admin) that pass router matching, rewrite to a traversal path, and resolve on downstream backends to restricted administrative endpoints. This allows complete bypass of route-level authentication controls such as BasicAuth, DigestAuth, or ForwardAuth.
Mitigation
Modify Kubernetes Ingress path rules to enforce explicit directory separators before captured regex groups (e.g., /api/(.*) instead of /api(.*)). Alternatively, disable the Ingress NGINX provider or enforce authentication at an upstream API gateway or mesh layer until patched.
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 | 9.1 | 7.5 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | High | None | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Understanding the Weakness (CWE)
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
The attacker may be able to create or overwrite critical files that are used to execute code, such as programs or libraries.
Integrity
Technical Impact: Modify Files or Directories
The attacker may be able to overwrite or create critical files, such as programs, libraries, or important data. If the targeted file is used for a security mechanism, then the attacker may be able to bypass that mechanism. For example, appending a new account at the end of a password file may allow an attacker to bypass authentication.
Confidentiality
Technical Impact: Read Files or Directories
The attacker may be able read the contents of unexpected files and expose sensitive data. If the targeted file is used for a security mechanism, then the attacker may be able to bypass that mechanism. For example, by reading a password file, the attacker could conduct brute force password guessing attacks in order to break into an account on the system.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
The attacker may be able to overwrite, delete, or corrupt unexpected critical files such as programs, libraries, or important data. This may prevent the product from working at all and in the case of protection mechanisms such as authentication, it has the potential to lock out product users.
Frequently Asked Questions
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