Vulnerability · Published May 8, 2026 · Assigned by GitHub_M

CVE-2026-41161Username Enumeration via Timing Attack

Medium 6.9

In plain English

A medium-severity security flaw in server from Sync-in. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 27% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)6.9Medium

Exploit odds (30 days)0.3%top 73.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Sync-in Server is a secure, open-source platform for file storage, sharing, collaboration, and syncing. Prior to version 2.2.0, the /api/auth/login endpoint contains a logic flaw that allows unauthenticated remote attackers to enumerate valid usernames by measuring the application's response time. This issue has been patched in version 2.2.0.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	@sync-in/server	2.2.0	GHSA-43fj-qp3h-hrh5

Affected products (as reported)

Vendor	Product	Versions
Sync-in	server	< 2.2.0

Weakness: CWE-208 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

References

https://github.com/Sync-in/server/security/advisories/GHSA-43fj-qp3h-hrh5 x_refsource_CONFIRM
https://github.com/Sync-in/server/releases/tag/v2.2.0 x_refsource_MISC