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.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact Low

Integrity Impact None

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
gofiber fiber affected
Version Status Constraints
< 3.3.0 affected —

No data.

No data.

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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
Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/gofiber/fiber/commit/c7ac00edd19f9669b1aebbec6e229658baaa059e cve-icon
https://github.com/gofiber/fiber/pull/4245 cve-icon
https://github.com/gofiber/fiber/releases/tag/v3.3.0 cve-icon
https://github.com/gofiber/fiber/security/advisories/GHSA-g5vh-55hw-rxm8 cve-icon
History

Wed, 08 Jul 2026 20:45:00 +0000

Type Values Removed Values Added
First Time appeared Gofiber
Gofiber fiber
Vendors & Products Gofiber
Gofiber fiber

Wed, 08 Jul 2026 19:45:00 +0000

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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-07-08T19:32:15.113Z

Reserved: 2026-05-05T19:52:59.146Z

Link: CVE-2026-44332

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-07-08T20:30:04Z

Weaknesses