CVE-2026-67191 (GCVE-0-2026-67191)

Vulnerability from cvelistv5 – Published: 2026-07-29 15:50 – Updated: 2026-08-14 16:50
VLAI
Title
Xlight FTP Server < 3.9.5 Pre-Auth Heap Buffer Overflow via SSH Parser
Summary
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.
Severity
9.3 (Critical)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-29 16:32 UTC
CWE
  • CWE-122 - Heap-based Buffer Overflow
Assigner
VulnCheck CNA under the mitre root
CNA scorecard B 84/100 over 7131 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Xlight Xlight FTP Server Affected: 0 , < 3.9.5 (semver)
    cpe:2.3:a:xlightftpd:xlight_ftp_server:*:*:*:*:*:*:*:*
Create a notification for this product.
Date Public
2026-07-01 00:00
Credits
McCaulay Hudson (@_McCaulay) of watchTowr
Show details on NVD website
To clipboard 

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