CVE-2026-71326
Description
A flaw was found in Traefik. The BasicAuth middleware in Traefik reuses a key for concurrent password checks, which is generated by concatenating the password and secret without a delimiter. An attacker with a valid credential and the corresponding stored hash can exploit this vulnerability to authenticate as an unconfigured username. This identity spoofing is possible when the 'headerField' is configured to trust forwarded identity information.
Statement
Red Hat OpenShift Dev Spaces bundles Traefik as a reverse proxy component. The shipped Traefik versions (3.27.1, 3.28.2, 3.29) are newer than the versions affected by this flaw (3.6.11-3.6.25 and 3.7.0-3.7.10), which are already fixed in the shipped releases. No Red Hat product is affected.
Mitigation
No mitigation is necessary; Red Hat products ship Traefik versions outside the vulnerable range.
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 | 3.8 | 3.8 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | High | High | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | Low | Low | N/A |
| Integrity Impact | Low | Low | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity
An attacker could bypass the authentication routine without knowing the original password.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
