Buffer overflow in Xlight Ftp Server
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…
Vulnerability class: Buffer Overflow
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Xlight Ftp Server — versions 0
Weakness classification (CWE)
References
- disclosure@vulncheck.com (third-party-advisory)
- disclosure@vulncheck.com (release-notes)
Frequently asked questions
- What is CVE-2026-67191?
- CVE-2026-67191 is a critical-severity vulnerability in Xlight Ftp Server, classified under Heap-based Buffer Overflow. CVSS score: 9.8/10. Published 2026-07-29.
- How severe is CVE-2026-67191?
- Critical severity. CVSS v3 base score is 9.8 out of 10.