{"schema_version":"1","data":[{"id":1961,"advisory_id":"46038aed-834e-4d8e-9770-1fa6a272e272","revision":1,"source_id":"core-cve","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-58271","source_published_at":"2026-09-21T19:50:14.539+00:00","published_at":"2026-10-24T21:10:50.834948+00:00","extraction_method":"structured","technologies":["core-cve","server"],"cve_ids":["CVE-2026-58271"],"event_types":["advisory"],"payload":{"kind":"advisory","title":"@sync-in/server vulnerable to TOTP Brute-Force via `POST /api/app/sync/register`","summary":"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.","evidence":"cve:CVE-2026-58271","products":[{"name":{"value":"server","evidence":"/containers/cna/affected/0/product"},"prerequisites":[],"fixed_versions":[],"affected_versions":[]}],"severity":"medium","structured":{"id":"CVE-2026-58271","aliases":["CVE-2026-58271"],"metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":6.8,"attackVector":"NETWORK","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N","integrityImpact":"HIGH","userInteraction":"NONE","attackComplexity":"HIGH","availabilityImpact":"NONE","privilegesRequired":"LOW","confidentialityImpact":"HIGH"}}],"affected":[{"vendor":"Sync-in","product":"server","versions":[{"status":"affected","version":"< 2.4.0"}]}],"modified":"2026-09-24T22:36:41.527Z","provider":"cve","references":["https://github.com/Sync-in/server/security/advisories/GHSA-274f-6w77-8qm9"],"provider_metadata":{"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-58271","role":"CISA Coordinator","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-09-24T22:35:57.537707Z"}}}],"references":[{"url":"https://github.com/Sync-in/server/security/advisories/GHSA-274f-6w77-8qm9","tags":["exploit"]}],"providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-09-24T22:36:41.527Z"}}],"cna":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-09-21T19:50:14.539Z"}}},"related_cves":[{"value":"CVE-2026-58271","evidence":"/cveMetadata/cveId"}],"security_relevant":true,"severity_evidence":"/containers/cna/metrics"},"priority":{"reasons":[],"severity":"medium","linked_cves":[],"fix_available":false,"known_exploited":false,"publisher_severity":"medium"},"context_update":false}],"next_after":1961,"next_before":1961}