CVE-2026-47684: Sync-In Server

High severity, CVSS 7.7. EPSS: 0.4% chance of exploitation in the next 30 days.

Sync-in Server is a secure, open-source platform for file storage, sharing, collaboration, and syncing. Prior to version 2.3.0, the private IP blocklist regex used in the URL download feature does not match IPv4-mapped IPv6 addresses (e.g. ::ffff:127.0.0.1), allowing SSRF protection to be bypassed on dual-stack systems. Version 2.3.0 fixes the issue.

Affected products

• Sync-In Server: before 2.3.0 (fixed in 2.3.0)

Published 2026-06-16. Last modified 2026-06-17.