CVE-2026-41263

Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a timing side-channel vulnerability in Traefik's BasicAuth middleware that allows an attacker to enumerate valid usernames through response-time differences. The variable intended to hold a constant-time fallback secret always resolves to an empty string, causing the constant-time comparison to short-circuit in microseconds rather than performing a full bcrypt evaluation. This restores the original timing oracle and makes it possible to distinguish existing users from non-existing ones by measuring authentication response times. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2.

CVSS v3 3.7 LOW

3.7^/10

CVSS v3 : LOW

Vector :

Exploitability : 2.2 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/traefik/traefik/releases/tag/v2.11.43	Product Release Notes
https://github.com/traefik/traefik/releases/tag/v3.6.14	Product Release Notes
https://github.com/traefik/traefik/releases/tag/v3.7.0-rc.2	Product Release Notes
https://github.com/traefik/traefik/security/advisories/GHSA-6x2q-h3cr-8j2h	Patch Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:traefik:traefik::::::::
	cpe:2.3:a:traefik:traefik::::::::
	cpe:2.3:a:traefik:traefik:3.7.0:ea1::::::
	cpe:2.3:a:traefik:traefik:3.7.0:ea2::::::
	cpe:2.3:a:traefik:traefik:3.7.0:ea3::::::
	cpe:2.3:a:traefik:traefik:3.7.0:rc1::::::

History

No history.

Information

Published : 2026-04-30 21:16

Updated : 2026-06-17 10:46

NVD link : CVE-2026-41263

Mitre link : CVE-2026-41263

CVE.ORG link : CVE-2026-41263

JSON object : View

Products Affected

traefik

traefik

CWE

CWE-208

Observable Timing Discrepancy

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