CVE-2026-47684Public exploitNetwork attack vector

Authenticated SSRF via IPv4-mapped IPv6 blocklist bypass

Published Jun 16, 2026 · Updated Jun 16, 2026

SSRF in Sync-in Server before 2.3.0 allows remote authenticated users to read internal resources through the URL download feature. The regExpPrivateIP check omits IPv4-mapped IPv6 forms, so downloadFromUrl accepts private destinations represented with an ::ffff prefix. Access to the file download feature and a dual-stack deployment are required; the server can fetch addresses that its blocklist should reject.

CVSS severity7.7
High
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

SSRF in Sync-in Server before 2.3.0 allows remote authenticated users to read internal resources through the URL download feature. The regExpPrivateIP check omits IPv4-mapped IPv6 forms, so downloadFromUrl accepts private destinations represented with an ::ffff prefix. Access to the file download feature and a dual-stack deployment are required; the server can fetch addresses that its blocklist should reject.

The record

CVE
CVE-2026-47684
Published
Jun 16, 2026
Updated
Jun 16, 2026
Vendor
Sync-in
Product
Sync-in Server
Classifications
CWE-918, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Sync-in · Sync-in Serverversion=< 2.3.0

Published CVSS scores

7.7GitHub CNACVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
T1190Exploit Public-Facing Application

Public exploit references

  • poc.pdfproof of concept · demonstrated

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo