CVE-2026-67191 (GCVE-0-2026-67191)
Vulnerability from cvelistv5 – Published: 2026-07-29 15:50 – Updated: 2026-08-14 16:50
VLAI
EPSS
VEX
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
9.8 (Critical)
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
References
2 references
| URL | Tags |
|---|---|
| https://www.xlightftpd.com/whatsnew.htm | release-notes |
| https://www.vulncheck.com/advisories/xlight-ftp-s… | third-party-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Xlight | Xlight FTP Server |
Affected:
0 , < 3.9.5
(semver)
cpe:2.3:a:xlightftpd:xlight_ftp_server:*:*:*:*:*:*:*:* |
Date Public
2026-07-01 00:00
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Nomenclature
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