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[ CVE-2026-58269 · Published 21 Sep 2026 ]

Sync-in Server has a complete 2FA Bypass via `POST /api/auth/token`

CVSS 8.1 EPSS <1%Fix available

[ Why it matters ]Priority signals

  • Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

Sync-in Server is an open-source platform for file storage, sharing, collaboration, and syncing. Prior to version 2.4.0, `POST /api/auth/token` authenticates with username and password only, then calls `getTokens()`, which returns full access and refresh JWTs without checking whether the account has TOTP 2FA enabled. An attacker with stolen or phished credentials can bypass 2FA in a single request. The parallel login endpoint (`POST /api/auth/login`) correctly enforces 2FA by calling `setCookies(user, res, true)`, which gates on `user.twoFaEnabled`. Version 2.4.0 patches the issue.

[ Fixes ]Fixes and patches

  • @sync-in/server 2.4.0Fixed version · GitHub Advisories · npm package @sync-in/server: upgrade to 2.4.0 or later (affected <= 2.3.0)

[ Packages ]Affected open-source packages

[ References ]References