VULNERABILITY INTELLIGENCE

CVE-2026-67191

CVSS score9.8 CRITICAL
EPSS probability0.96%
CISA KEVNot currently listed
Published2026-07-29
Last modified2026-10-23
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Description

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.

Weakness classification

  • disclosure@vulncheck.com: CWE-122

Primary references