CVE-2026-58270: Sync-in server · ReDoS
Affects Sync-in serverSource CVE Database V5
Not known to be exploited · CVSS 6.5 Medium : upgrade to 2.4.0 when convenient.
Data as of 5 Nov 2026, 00:01 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 35% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 2.4.0
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 21 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Upgrade server and sync-in/server to 2.4.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Sync-inserver | Affected
| Fixed in
|
GitHubsync-in/serverpkg:github/sync-in/serverOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade to Sync-in Server version 2.4.0 or later, where the vulnerability is patched. No other mitigation is indicated or required.
Description
Sync-in Server versions prior to 2.4.0 contain a vulnerability in the sync diff endpoint where user-supplied strings are compiled into regular expressions without complexity validation. This can lead to catastrophic backtracking patterns that block the Node.js event loop, causing the server to become unresponsive until restarted. The issue is patched in version 2.4.0.