Buffer overflow in Xlight FTP Server

CVE-2026-67192

Xlight FTP Server before 3.9.5 contains a pre-authentication stack buffer overflow vulnerability that allows unauthenticated attackers to corrupt stack memory by sending malformed SSH packets when a GCM cipher is negotiated. Attackers can craft packets with an unvalidated length field passed directly to the GCM decrypt function, overwriting the stack cookie and return address to potentially achieve remote code execution before any authentication occurs.

Vulnerability class: Buffer Overflow

EPSS: 0.007 (49.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-67192?
CVE-2026-67192 is a high-severity vulnerability in Xlight FTP Server, classified under Stack-based Buffer Overflow. CVSS score: 8.1/10. Published 2026-07-29.
How severe is CVE-2026-67192?
High severity. CVSS v3 base score is 8.1 out of 10.