CVE-2026-44332 MEDIUM

CVE-2026-44332: Fiber: Username Enumeration via Timing Oracle in BasicAuth Default Authorizer

Vendor Gofiber
Product fiber
Weakness CWE-203
Published July 8, 2026
Last update July 9, 2026

CVSS base score

5.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality Low
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

What the vulnerability does

01Description

Fiber is an Express inspired web framework written in Go. Prior to 3.3.0, the default Authorizer function in the BasicAuth middleware in middleware/basicauth/config.go uses short-circuit evaluation that skips password hash comparison for non-existent usernames, enabling reliable remote username enumeration through response timing differences. This issue is fixed in version 3.3.0.

Key dates

02Disclosure timeline

July 8, 2026 CVE published
July 9, 2026 Record updated