Sync-in Server has a ReDoS via Unsanitized Regex in Sync Diff `pathFilters`
Priority MEDIUM 62CWE-1333Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-1333.
Summary
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.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00411 35th percentileScored 2026-11-07
Fix Fixed server (Sync-in): 2.4.0@sync-in/server (npm): 2.4.0
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Sync-in | server | before 2.4.0 | 2.4.0 | Patch available | CNA |
| — | @sync-in/server (npm) | before 2.4.0 | 2.4.0 | Patch available | GHSA-jx63-h26r-8cph |
- server VendorSync-in Affected before 2.4.0 Fixed in 2.4.0 Patch available CNA
- @sync-in/server (npm) Vendor— Affected before 2.4.0 Fixed in 2.4.0 Patch available GHSA-jx63-h26r-8cph
Remediation
- Fix · CNA server (Sync-in) Fixed in 2.4.0
- Fix · GHSA-jx63-h26r-8cph @sync-in/server (npm) Fixed in 2.4.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-58270
- 2026-10-03 Alias added: GHSA-jx63-h26r-8cph
References
More Sync-in vulnerabilities
- TI-2026-41960 Sync-in Server has a complete 2FA Bypass via `POST /api/auth/token` CVSS 3.1HIGH 8.1
- TI-2026-29787 Username Enumeration via Timing Attack CVSS 4.0MEDIUM 6.9
- TI-2026-35188 Sync-in Server: SSRF protection bypass via IPv4-mapped IPv6 addresses in regExpPrivateIP CVSS 3.1HIGH 7.7
- TI-2026-41962 @sync-in/server vulnerable to TOTP Brute-Force via `POST /api/app/sync/register` CVSS 3.1MEDIUM 6.8
- TI-2026-41963 Sync-in Server has Username/Login Enumeration via Timing Side-Channel on POST… CVSS 3.1MEDIUM 5.3
- TI-2025-41214 A Stored Cross-Site Scripting (XSS) vulnerability in Sync-in Server before 1.9.3 allows… CVSS 3.1MEDIUM 6.1
Sources
- CVE-2026-58270 · CVE Program
- CVE-2026-58270 · NVD
- FIRST EPSS
- GHSA-jx63-h26r-8cph · GitHub Advisory Database · CC BY 4.0
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