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 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.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://www.vulncheck.com/advisories/xlight-ftp-server-pre-auth-heap-buffer-overflow-via-ssh-parser
https://www.xlightftpd.com/whatsnew.htm

Configurations

No configuration.

History

29 Jul 2026, 16:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-29 16:17

Updated : 2026-07-30 20:04

NVD link : CVE-2026-67191

Mitre link : CVE-2026-67191

CVE.ORG link : CVE-2026-67191

JSON object : View

Products Affected

No product.

CWE

CWE-122

Heap-based Buffer Overflow

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