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.
Fix
Patch, vendor advisory and mitigation references on NVD 3
- https://github.com/gofiber/fiber/commit/c7ac00edd19f9669b1aebbec6e229658baaa059e Patch
- https://github.com/gofiber/fiber/pull/4245 Issue Tracking, Patch
- https://github.com/gofiber/fiber/security/advisories/GHSA-g5vh-55hw-rxm8 Exploit, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 5.3 · gofiberNVD modified 2026-10-25 17:10
Affected (CPE criteria) 1
cpe:2.3:a:gofiber:fiber:*:*:*:*:*:go:*:*
References 4
- https://github.com/gofiber/fiber/commit/c7ac00edd19f9669b1aebbec6e229658baaa059e Patch
- https://github.com/gofiber/fiber/pull/4245 Issue Tracking, Patch
- https://github.com/gofiber/fiber/releases/tag/v3.3.0 Release Notes
- https://github.com/gofiber/fiber/security/advisories/GHSA-g5vh-55hw-rxm8 Exploit, Vendor Advisory