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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| gofiber | fiber | < 3.3.0 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | golang-github-gofiber-fiber | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | govulncheck-vulndb | 0.0.20260727T201416-160000.1.1 | SUSE-SU-2026:23227-1, SUSE-SU-2026:23216-1 |
| SLES 16.0 | govulncheck-vulndb | 0.0.20260727T201416-160000.1.1 | SUSE-SU-2026:23227-1, SUSE-SU-2026:23216-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | govulncheck-vulndb | 0.0.20260727T201416-160000.1.1 | openSUSE-SU-2026:21551-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Go | github.com/gofiber/fiber/v3 | < 3.3.0 | 3.3.0 | GHSA-g5vh-55hw-rxm8 |
Advisories 3
- SUSE-SU-2026:23227-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:23216-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Aug 27, 2026
- openSUSE-SU-2026:21551-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Aug 12, 2026