CVE-2026-58272

Sync-in Server has Username/Login Enumeration via Timing Side-Channel on POST /api/auth/login (incomplete fix of the prior timing-attack advisory)

MEDIUM
5.3
CVSS Score
Published: September 21, 2026 at 08:31 PM UTC
Updated: September 30, 2026 at 05:32 PM UTC
1 product affected across 1 vendorSync-in Server

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.4%
SSVC
PoC

Description

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.

Affected

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

v < 2.4.1
Affected range stops below 2.4.1, 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

SSVCPoCAutomatablePartial impact

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

CVSS

5.3MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-208

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