CVE-2026-47684 json
Sync-in Server: SSRF protection bypass via IPv4-mapped IPv6 addresses in regExpPrivateIP
published 5mo ago modified 17d ago also EUVD-2026-37123 , GHSA-q4x5-8cj6-52wg
- cvss
- 7.7
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 12%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- npm @sync-in/server 2.3.0
- sync-in sync-in_server 2.3.0
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Check with FencerCISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 4mo ago
Exploit prediction
0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-11).
Exploits and checks
- github.com https://github.com/Sync-in/server/security/advisories/GHSA-q4x5-8cj6-52wg referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N |
| GitHub | 3.1 | 7.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | @sync-in/server | <2.3.0 |
2.3.0 |
Affected products
- Sync-in server
Classification
- Weakness
-
- CWE-918 Server-Side Request Forgery
References
Sources
- CVE List CVE-2026-47684
- GitHub Advisory GHSA-q4x5-8cj6-52wg
- NVD CVE-2026-47684
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.