{"id":"CVE-2026-44332","aliases":["GHSA-g5vh-55hw-rxm8","GO-2026-5886"],"url":"https://o3.security/vulnerability/CVE-2026-44332","summary":"Fiber: Username Enumeration via Timing Oracle in BasicAuth Default Authorizer","details":"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.","published":"2026-07-08T19:32:15.113Z","modified":"2026-08-27T18:26:11.802905005Z","cvss":{"score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"},"epss":{"score":0.00517,"percentile":0.42137,"asOf":"2026-09-08"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/gofiber/fiber/v3","fixedVersion":"3.3.0"}],"fix":{"url":"https://github.com/gofiber/fiber/commit/c7ac00edd19f9669b1aebbec6e229658baaa059e","label":"gofiber/fiber@c7ac00e"},"references":[{"type":"WEB","url":"https://github.com/gofiber/fiber/releases/tag/v3.3.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44332.json"},{"type":"ADVISORY","url":"https://github.com/gofiber/fiber/security/advisories/GHSA-g5vh-55hw-rxm8"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44332"},{"type":"FIX","url":"https://github.com/gofiber/fiber/commit/c7ac00edd19f9669b1aebbec6e229658baaa059e"},{"type":"FIX","url":"https://github.com/gofiber/fiber/pull/4245"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-27T18:26:11.802905005Z"}}