CVE-2026-67192

Xlight FTP Server < 3.9.5 Pre-Auth Stack Buffer Overflow via SSH GCM Cipher

HIGH
8.1
CVSS Score
Published: July 29, 2026 at 03:51 PM UTC
Updated: October 23, 2026 at 11:10 PM UTC
2 products affected across 2 vendorsXlight FTP ServerXlight FTP Server

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Severity
HIGH8.1
Exploit prediction
EPSS 1%
SSVC
No known exploit

Description

Xlight FTP Server before 3.9.5 contains a pre-authentication stack buffer overflow vulnerability that allows unauthenticated attackers to corrupt stack memory by sending malformed SSH packets when a GCM cipher is negotiated. Attackers can craft packets with an unvalidated length field passed directly to the GCM decrypt function, overwriting the stack cookie and return address to potentially achieve remote code execution before any authentication occurs.

Affected

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

v < 3.9.5
Affected range stops below 3.9.5, so it looks safe — our inference, not a vendor statement
0 ≤ v < 3.9.50
Affected range stops below 3.9.5, 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.

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

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

CVSS

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

Quick Info

StatusDEFERRED
CWE
CWE-121

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