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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-67191 Detail

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.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  VulnCheck
CVSS-B 9.3 CRITICAL
Vector:  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

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://www.vulncheck.com/advisories/xlight-ftp-server-pre-auth-heap-buffer-overflow-via-ssh-parser VulnCheck
https://www.xlightftpd.com/whatsnew.htm VulnCheck

Weakness Enumeration

CWE-ID CWE Name Source
CWE-122 Heap-based Buffer Overflow VulnCheck  

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-67191
NVD Published Date:
07/29/2026
NVD Last Modified:
07/29/2026
Source:
VulnCheck