{"id":"CVE-2026-23849","state":"PUBLISHED","title":"File Browser vulnerable to Username Enumeration via Timing Attack in /api/login","description":"File Browser provides a file managing interface within a specified directory and can be used to upload, delete, preview, rename, and edit files. Prior to version 2.55.0, the JSONAuth. Auth function contains a logic flaw that allows unauthenticated attackers to enumerate valid usernames by measuring the response time of the /api/login endpoint. The vulnerability exists due to a \"short-circuit\" evaluation in the authentication logic. When a username is not found in the database, the function returns immediately. However, if the username does exist, the code proceeds to verify the password using bcrypt (users.CheckPwd), which is a computationally expensive operation designed to be slow. This difference in execution path creates a measurable timing discrepancy. Version 2.55.0 contains a patch for the issue.","publishedAt":"2026-01-19T20:37:29.716Z","updatedAt":"2026-01-20T15:54:36.499Z","severity":{"score":5.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["filebrowser filebrowser"],"affected":[{"vendor":"filebrowser","product":"filebrowser","versions":[{"version":"< 2.55.0","status":"affected"}]}],"references":["https://github.com/filebrowser/filebrowser/security/advisories/GHSA-43mm-m3h2-3prc","https://github.com/filebrowser/filebrowser/commit/24781badd413ee20333aba5cce1919d676e01889"],"weaknesses":["CWE-208"],"ingestedAt":"2026-10-29T20:11:21.040Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/23xxx/CVE-2026-23849.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-23849","state":"PUBLISHED","datePublished":"2026-01-19T20:37:29.716Z","dateUpdated":"2026-01-20T15:54:36.499Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-01-16T15:46:40.843Z"},"containers":{"cna":{"title":"File Browser vulnerable to Username Enumeration via Timing Attack in /api/login","descriptions":[{"lang":"en","value":"File Browser provides a file managing interface within a specified directory and can be used to upload, delete, preview, rename, and edit files. Prior to version 2.55.0, the JSONAuth. Auth function contains a logic flaw that allows unauthenticated attackers to enumerate valid usernames by measuring the response time of the /api/login endpoint. The vulnerability exists due to a \"short-circuit\" evaluation in the authentication logic. When a username is not found in the database, the function returns immediately. However, if the username does exist, the code proceeds to verify the password using bcrypt (users.CheckPwd), which is a computationally expensive operation designed to be slow. This difference in execution path creates a measurable timing discrepancy. Version 2.55.0 contains a patch for the issue."}],"affected":[{"vendor":"filebrowser","product":"filebrowser","versions":[{"version":"< 2.55.0","status":"affected"}]}],"references":[{"url":"https://github.com/filebrowser/filebrowser/security/advisories/GHSA-43mm-m3h2-3prc","name":"https://github.com/filebrowser/filebrowser/security/advisories/GHSA-43mm-m3h2-3prc","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/filebrowser/filebrowser/commit/24781badd413ee20333aba5cce1919d676e01889","name":"https://github.com/filebrowser/filebrowser/commit/24781badd413ee20333aba5cce1919d676e01889","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.3,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-208","lang":"en","description":"CWE-208: Observable Timing Discrepancy","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-01-19T20:37:29.716Z"},"source":{"advisory":"GHSA-43mm-m3h2-3prc","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-01-20T15:54:21.087323Z","id":"CVE-2026-23849","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-01-20T15:54:36.499Z"}}]}}}