CVE-2026-47684

Sync-in Server: SSRF protection bypass via IPv4-mapped IPv6 addresses in regExpPrivateIP

Published Jun 16, 2026 CVSS 3.1 · 7.7 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-q4x5-8cj6-52wg Sync-in Server: SSRF protection bypass via IPv4-mapped IPv6 addresses in regExpPrivateIP
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Sync-in
Sync-in server
Vendors & Products Sync-in
Sync-in server
Type Values Removed Values Added
Description 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.
Title Sync-in Server: SSRF protection bypass via IPv4-mapped IPv6 addresses in regExpPrivateIP
Weaknesses CWE-918
References
Metrics cvssV3_1

{'score': 7.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jun 16, 2026, 5:10 PM
Reserved
May 19, 2026, 9:18 PM
Status
Deferred
Published
Jun 16, 2026, 3:16 PM
Modified
Oct 25, 2026, 11:10 PM