Vulnerability · Published Sep 21, 2026 · Assigned by GitHub_M

CVE-2026-58269Sync-in Server has a complete 2FA Bypass via `POST /api/auth/token`

High 8.1

In plain English

A high-severity authentication bypass 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 20% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)0.3%top 80.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Sync-in Server is an open-source platform for file storage, sharing, collaboration, and syncing. Prior to version 2.4.0, `POST /api/auth/token` authenticates with username and password only, then calls `getTokens()`, which returns full access and refresh JWTs without checking whether the account has TOTP 2FA enabled. An attacker with stolen or phished credentials can bypass 2FA in a single request. The parallel login endpoint (`POST /api/auth/login`) correctly enforces 2FA by calling `setCookies(user, res, true)`, which gates on `user.twoFaEnabled`. Version 2.4.0 patches the issue.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	@sync-in/server	2.4.0	GHSA-92cr-jxw4-5wjg

Affected products (as reported)

Vendor	Product	Versions
Sync-in	server	< 2.4.0

Weakness: CWE-288 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

References

https://github.com/Sync-in/server/security/advisories/GHSA-92cr-jxw4-5wjg x_refsource_CONFIRM