CVE-2026-58272 json
Sync-in Server has Username/Login Enumeration via Timing Side-Channel on POST /api/auth/login (incomplete fix of the prior timing-attack advisory)
published 2026-09-21 48 d ago modified 2026-09-30 39 d ago also GHSA-29hq-23m2-2j47 , EUVD-2026-84199
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 33%
- public exploits
- 0
- none known
Summary
Sync-in Server is an open-source platform for file storage, sharing, collaboration, and syncing. Versions prior to 2.4.1 contain an observable timing discrepancy in the login endpoint because authentication attempts for nonexistent accounts return without performing the bcrypt comparison used for existing accounts. An unauthenticated attacker can measure response times to enumerate valid usernames or email addresses, facilitating credential-stuffing, password-spraying, and phishing attacks. Version 2.4.1 contains a patch.
Patch / fix
- npm @sync-in/server 2.4.1
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 46 d ago
Exploit prediction
0.39% chance of exploitation in the next 30 days, higher than 33% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/Sync-in/server/security/advisories/GHSA-29hq-23m2-2j47 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
| GitHub | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | @sync-in/server | <2.4.1 |
2.4.1 |
Affected products
- Sync-in server
Classification
- Weakness
-
- CWE-208 Observable Timing Discrepancy
References
Sources
- CVE List CVE-2026-58272
- GitHub Advisory GHSA-29hq-23m2-2j47
- NVD CVE-2026-58272
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