CVE-2026-58269

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

HIGH
8.1
CVSS Score
Published: September 21, 2026 at 08:01 PM UTC
Updated: September 24, 2026 at 11:17 PM UTC
1 product affected across 1 vendorSync-in Server

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Severity
HIGH8.1
Exploit prediction
EPSS 0.3%
SSVC
PoC

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.4.0
Affected range stops below 2.4.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

SSVC — Action Prioritization

SSVCPoCNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.1HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-288

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