TI-2026-41963 Aliases CVE-2026-58272 GHSA-29hq-23m2-2j47

Sync-in Server has Username/Login Enumeration via Timing Side-Channel on POST…

MEDIUM 63CWE-208Published 2026-09-21 · Updated 2026-09-23

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Information disclosure
Confidentiality · integrity · availability: Low · None · None
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-208.

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00394 33rd percentileScored 2026-11-07

Fix Fixed server (Sync-in): 2.4.1@sync-in/server (npm): 2.4.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Sync-in	server	before 2.4.1	2.4.1	Patch available	CNA
—	@sync-in/server (npm)	before 2.4.1	2.4.1	Patch available	GHSA-29hq-23m2-2j47

server VendorSync-in Affected before 2.4.1 Fixed in 2.4.1 Patch available CNA
@sync-in/server (npm) Vendor— Affected before 2.4.1 Fixed in 2.4.1 Patch available GHSA-29hq-23m2-2j47

Remediation

Fix · CNA server (Sync-in) Fixed in 2.4.1
Fix · GHSA-29hq-23m2-2j47 @sync-in/server (npm) Fixed in 2.4.1 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-58272
2026-10-03 Alias added: GHSA-29hq-23m2-2j47

References

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2026-58272

Other 4

TI-2026-41960 Sync-in Server has a complete 2FA Bypass via `POST /api/auth/token` CVSS 3.1HIGH 8.1
TI-2026-29787 Username Enumeration via Timing Attack CVSS 4.0MEDIUM 6.9
TI-2026-35188 Sync-in Server: SSRF protection bypass via IPv4-mapped IPv6 addresses in regExpPrivateIP CVSS 3.1HIGH 7.7
TI-2026-41962 @sync-in/server vulnerable to TOTP Brute-Force via `POST /api/app/sync/register` CVSS 3.1MEDIUM 6.8
TI-2026-41961 Sync-in Server has a ReDoS via Unsanitized Regex in Sync Diff `pathFilters` CVSS 3.1MEDIUM 6.5
TI-2025-41214 A Stored Cross-Site Scripting (XSS) vulnerability in Sync-in Server before 1.9.3 allows… CVSS 3.1MEDIUM 6.1

See all 7 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences