CVE-2026-44332
MEDIUMFiber: Username Enumeration via Timing Oracle in BasicAuth Default Authorizer
Title source: cnaDescription
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.
References (4)
Core 4
Core References
X_Refsource_Confirm x_refsource_confirm
https://github.com/gofiber/fiber/security/advisories/GHSA-g5vh-55hw-rxm8
X_Refsource_Misc x_refsource_misc
https://github.com/gofiber/fiber/pull/4245
X_Refsource_Misc x_refsource_misc
https://github.com/gofiber/fiber/commit/c7ac00edd19f9669b1aebbec6e229658baaa059e
X_Refsource_Misc x_refsource_misc
https://github.com/gofiber/fiber/releases/tag/v3.3.0
Scores
CVSS v3
5.3
EPSS
0.0052
EPSS Percentile
40.2%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-203
Status
published
Products (1)
gofiber/fiber
< 3.3.0
Published
Jul 08, 2026
Tracked Since
Jul 09, 2026