SSRF in Sync-In Server

CVE-2026-47684

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.

Vulnerability class: SSRF (Server-Side Request Forgery)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.002 (12.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 12.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-47684: held from 0.004 to 0.002.

EPSS over last 30 days · oldest: 0.004 · newest: 0.002 · change: -0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-47684?
CVE-2026-47684 is a high-severity vulnerability in Sync-In Server, classified under Server-Side Request Forgery (SSRF). CVSS score: 7.7/10. Published 2026-06-16.
How severe is CVE-2026-47684?
High severity. CVSS v3 base score is 7.7 out of 10.