CVE-2026-53994: ProFTPD mod_sftp contains a heap-based buffer overflow reachable by an authenticated SFTP user

Q: How do I fix CVE-2026-53994?

proftpd: upgrade to 1.3.10. Exact commands for each OS are on this page.

Q: Is CVE-2026-53994 being exploited?

CVE-2026-53994 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-53994 affect?

CVE-2026-53994 affects proftpd. Severity is high (CVSS 7.5). ProFTPD mod_sftp contains a heap-based buffer overflow reachable by an authenticated SFTP user. The fxp_packet_read() function accepts the attacker-supplied 32-bit big-endian SFTP packet length without a minimum sanity check. A value of 0 c

Routine

HIGH 7.5UPGRADE

CVE-2026-53994 is a high-severity flaw (CVSS 7.5) affecting proftpd. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

ProFTPD mod_sftp contains a heap-based buffer overflow reachable by an authenticated SFTP user. The fxp_packet_read() function accepts the attacker-supplied 32-bit big-endian SFTP packet length without a minimum sanity check. A value of 0 causes an unsigned subtraction elsewhere in the read path to underflow to approximately 4 GB. That oversized request reaches the core memory allocator, where the rounded size is computed in size_t but passed to

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.4% (top 64%)
CISA exploited list	No
Weakness	CWE-122
Published	2026-07-18
Last modified	2026-10-24

Publisher (CNA): VulnCheck · Vendor: proftpd

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-18 20:17 UTCPublished CVE record published
2026-10-24 20:10 UTCUpdated Record last modified

proftpd proftpd UPGRADE

Affected: < 1.3.10

Fixed in: 1.3.10

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy proftpd || rpm -q proftpd || proftpd --version

2. UPGRADE to 1.3.10 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade proftpd

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade proftpd

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-53994?

proftpd: upgrade to 1.3.10. Exact commands for each OS are on this page.

Is CVE-2026-53994 being exploited?

CVE-2026-53994 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-53994 affect?

CVE-2026-53994 affects proftpd. Severity is high (CVSS 7.5). ProFTPD mod_sftp contains a heap-based buffer overflow reachable by an authenticated SFTP user. The fxp_packet_read() function accepts the attacker-supplied 32-bit big-endian SFTP packet length without a minimum sanity check. A value of 0 c

How urgent is CVE-2026-53994?

Priority 35/100. High severity

Software pages

ProFTPD vulnerabilities

Related CVEs

CVE-2015-3306 CRITICAL 10.0 EXPLOITED MITIGATE MITIGATE ProFTPD Improper Access Control Vulnerability

References

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