What is CVE-2026-63091?

CVE-2026-63091 is a medium-severity vulnerability in Proftpd, classified under Buffer Over-read. CVSS score: 6.5/10. Published 2026-07-20.

How severe is CVE-2026-63091?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Integer overflow in Proftpd

CVE-2026-63091

ProFTPD before 1.3.9c and 1.3.10rc3 contains a signed integer overflow vulnerability in the mod_sftp module's SCP size-record parser that allows authenticated low-privilege attackers to bypass ASLR by sending a crafted file size value of U…

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

Affected products

Proftpd — versions 0, 1.3.10rc1

Weakness classification (CWE)

References

disclosure@vulncheck.com (release-notes)
disclosure@vulncheck.com (release-notes, patch)
disclosure@vulncheck.com (release-notes, patch)
disclosure@vulncheck.com (issue-tracking, patch)
disclosure@vulncheck.com (patch)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-63091?: CVE-2026-63091 is a medium-severity vulnerability in Proftpd, classified under Buffer Over-read. CVSS score: 6.5/10. Published 2026-07-20.
How severe is CVE-2026-63091?: Medium severity. CVSS v3 base score is 6.5 out of 10.