CVE-2026-44332

Fiber: Username Enumeration via Timing Oracle in BasicAuth Default Authorizer

Published Jul 8, 2026 CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-g5vh-55hw-rxm8 GoFiber Vulnerable to Username Enumeration via Timing Oracle in BasicAuth Default Authorizer
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Gofiber
Gofiber fiber
Vendors & Products Gofiber
Gofiber fiber
Type Values Removed Values Added
Description 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.
Title Fiber: Username Enumeration via Timing Oracle in BasicAuth Default Authorizer
Weaknesses CWE-203
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 9, 2026, 2:33 PM
Reserved
May 5, 2026, 7:52 PM
Status
Analyzed
Published
Jul 8, 2026, 8:16 PM
Modified
Oct 25, 2026, 5:10 PM