Vulnerability · Published Sep 21, 2026 · Assigned by GitHub_M

CVE-2026-58270Sync-in Server has a ReDoS via Unsanitized Regex in Sync Diff `pathFilters`

Medium 6.5

In plain English

A medium-severity regular-expression denial of service in server from Sync-in. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.4%top 64.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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 packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	@sync-in/server	2.4.0	GHSA-jx63-h26r-8cph

Affected products (as reported)

Vendor	Product	Versions
Sync-in	server	< 2.4.0

Weakness: CWE-1333 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References

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