Vulnerability · Published Jul 29, 2026 · Assigned by VulnCheck

CVE-2026-67192Xlight FTP Server < 3.9.5 Pre-Auth Stack Buffer Overflow via SSH GCM Cipher

High 8.1

In plain English

A high-severity stack buffer overflow in Xlight FTP Server from Xlight. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.0% (higher than 64% of all known vulnerabilities).

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)1.0%top 36.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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 products (as reported)

Vendor	Product	Versions
Xlight	Xlight FTP Server	0 – before 3.9.5

Weakness: CWE-121 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Changelog release-notes
https://www.vulncheck.com/advisories/xlight-ftp-server-pre-auth-stack-buffer-overflow-via-ssh-gcm-cipher third-party-advisory