{"id":"CVE-2026-58271","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-58271","generatedAt":"2026-10-27T23:56:47.969Z","title":"While the code is valid, the attacker can also call `POST /api/auth/2fa/disable` to permanently remove MFA.","description":"Sync-in Server is an open-source platform for file storage, sharing, collaboration, and syncing. Prior to version 2.4.0, `POST /api/app/sync/register` accepts credentials and a TOTP code to register a desktop sync client. On a failed TOTP, `SyncClientsManager.register()` calls `updateAccesses(user, ip, false)`, which hits a freeze branch that writes `passwordAttempts` back unchanged. The counter never reaches `USER_MAX_PASSWORD_ATTEMPTS` (10) and the lockout gate never fires. A successful guess returns a `{clientId, clientToken}` pair. The token can be exchanged via `POST /api/app/sync/auth/cookie` for a full JWT. While the code is valid, the attacker can also call `POST /api/auth/2fa/disable` to permanently remove MFA. Version 2.4.0 patches the issue.","published":"2026-09-21T20:17:27.000Z","lastModified":"2026-09-24T23:17:13.000Z","status":"Deferred","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":6.8,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N"},"cwe":["CWE-307"],"affected":[],"epss":{"score":0.00219,"percentile":0.12301,"date":"2026-10-26","history":[{"date":"2026-09-22","score":0.0018,"percentile":0.0782}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.22%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-21T20:17:27.000Z","detail":{"score":"6.8","severity":"MEDIUM","publishedAt":"2026-09-21T20:17:26.993Z"},"summary":"New CVE, medium severity (CVSS 6.8)."}],"references":[{"url":"https://github.com/Sync-in/server/security/advisories/GHSA-274f-6w77-8qm9","source":"security-advisories@github.com"},{"url":"https://github.com/Sync-in/server/security/advisories/GHSA-274f-6w77-8qm9","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-58271","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}