CVE-2026-67191 — Xlight FTP Server < 3.9.5 Pre-Auth Heap Buffer Overflow via SSH Parser
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 buff…
Published: 2026-07-29 · CVSS: 9.3 · CVSS 4.0
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7