CVE-2026-58270
Sync-in Server is an open-source platform for file storage, sharing, collaboration, and syncing. Prior to version 2.4.0, the sync diff endpoint compiles a user-supplied string into a `RegExp` with no complexity validation. A catastrophic-backtracking pattern (e.g. `^(a+)+b`) blocks the Node.js event loop, making the entire server unresponsive to all users until the container is restarted. Version 2.4.0 patches the issue.
- Published Sep 21, 2026
- CVSS 6.5 medium
- 0.3% chance of exploitation in the next 30 days (EPSS)
- A fix is available