Traefik up to 3.7.12 BasicAuth basic_auth.go CheckPassword information disclosure

Summaryinfo

A vulnerability described as problematic has been identified in Traefik up to 3.7.12. This affects the function CheckPassword of the file pkg/middlewares/auth/basic_auth.go of the component BasicAuth. The manipulation results in information disclosure. This vulnerability is cataloged as CVE-2026-88010. The attack may be launched remotely. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Traefik up to 3.7.12. Affected is the function CheckPassword of the file pkg/middlewares/auth/basic_auth.go of the component BasicAuth. The manipulation with an unknown input leads to a information disclosure vulnerability. CWE is classifying the issue as CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. This is going to have an impact on confidentiality. CVE summarizes:

Traefik is an open source HTTP reverse proxy and load balancer. From 3.6.11 until 3.7.13, checkPassword in pkg/middlewares/auth/basic_auth.go constructs the BasicAuth singleflight key from the submitted password and stored secret. Concurrent requests for absent usernames therefore coalesce on one key while configured usernames perform separate password hashes, creating an unauthenticated timing discrepancy that reveals whether a username exists. Sequential checks remain cost-equalized, Traefik v2 and Digest authentication are not affected, and the issue does not disclose credentials or bypass authentication. This issue is fixed in version 3.7.13.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-88010 since 09/09/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1592.

Upgrading to version 3.7.13 eliminates this vulnerability.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Name

• Traefik

Version

• 3.7.0
• 3.7.1
• 3.7.2
• 3.7.3
• 3.7.4
• 3.7.5
• 3.7.6
• 3.7.7
• 3.7.8
• 3.7.9
• 3.7.10
• 3.7.11
• 3.7.12

Website

• Product: https://github.com/traefik/traefik/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Discussion