CVE-2026-67191
Pre-auth heap overflow in Xlight FTP Server via malformed SSH client ID.
Is CVE-2026-67191 being exploited?
Not confirmed. CVE-2026-67191 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.62% probability of exploitation in the next 30 days.
How severe is CVE-2026-67191?
CVE-2026-67191 is rated Critical with a CVSS score of 9.3. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-67191?
Yes. A fix has been recorded for CVE-2026-67191. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-67191 affect?
CVE-2026-67191 affects Xlight FTP Server < 3.9.5, Xlight SFTP/SSH service. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-67191?
Upgrade to Xlight 3.9.5+ immediately or block SFTP/SSH access until patched.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote unauthenticated heap overflow on SSH/SFTP allowing potential remote code execution or denial of service before auth.
Immediate action required
- affected< 3.9.5
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.