Vulnerability intelligence

CVE-2026-67191

Xlight FTP Server before 3.9.5 contains a pre-authentication heap buffer overflow vulnerability that allows remote unauthenticated attackers to write past the end of a heap buffer by sending a malformed SSH client identification string. A logic error in the recv loop's termination condition uses an incorrect OR operator where an AND operator is required, enabling exploitation on any SSH or SFTP connection before authentication occurs.

CVSS Score

9.8

Critical

EPSS — Exploit Probability

0.6%

Riskier than 48% of all CVEs · checked 2026-09-14

Exploitation

Not in CISA KEV

KEV does not include every exploited vulnerability

Remediation

unknown

Check vendor advisories