CVE-2026-58270

Sync-in Server has a ReDoS via Unsanitized Regex in Sync Diff `pathFilters`

Published 21 Sep 2026 • Updated 21 Sep 2026

Severity: MEDIUM

Description

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.

Affected products (1)

• Sync-in server

Problem types

• CWE-1333: Inefficient Regular Expression Complexity

References (1)

• https://github.com/Sync-in/server/security/advisories/GHSA-jx63-h26r-8cph