Fiber: Username Enumeration via Timing Oracle in BasicAuth Default Authorizer (gofiber fiber)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.52 % · percentile 44 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Analyzed
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.
Weaknesses (CWE)
- CWE-203 — Observable Discrepancy
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N | GitHub_M |
| CVSS 3.1 | MEDIUM 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N | NVD · security-advisories@github.com (Secondary) |
Advisories
- GHSA-g5vh-55hw-rxm8 — GoFiber Vulnerable to Username Enumeration via Timing Oracle in BasicAuth Default Authorizer
- GO-2026-5886 — GoFiber Vulnerable to Username Enumeration via Timing Oracle in BasicAuth Default Authorizer in github.com/gofiber/fiber
European references
- ENISA EUVD · EUVD-2026-42358
- GCVE · GCVE-0-2026-44332
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:gofiber:fiber:*:*:*:*:*:go:*:*< 3.3.0
Affected products
| Product | Versions |
|---|---|
| gofiber · fiber | affected < 3.3.0 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |