CVE-2026-63447: Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring

This month

HIGH 7.5REMOTEDOWNGRADE

CVE-2026-63447 is a high-severity flaw (CVSS 7.5) affecting suricata. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. From 8.0.5 until 8.0.6, the FTP parser in src/app-layer-ftp.c can continue allocating transactions after app-layer.protocols.ftp.max-tx is reached while processing one large chunk of FTP command data. The oversized transaction list is repeatedly processed with quadratic complexity after the too_many_transactions event, allowing cr

Why this priority

High severity
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 50%)
CISA exploited list	No
Weakness	CWE-407
Published	2026-09-18
Last modified	2026-09-28

Publisher (CNA): GitHub, Inc. · Vendor: oisf

Last updated 2026-09-28 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-18 21:17 UTCPublished CVE record published
2026-09-28 18:34 UTCUpdated Record last modified

oisf suricata DOWNGRADE

Affected: 8.0.5

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.0.5

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 8.0.5 (Debian / Ubuntu)

apt-cache madison suricata sudo apt install suricata=<VERSION_BEFORE_8.0.5> sudo apt-mark hold suricata

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list suricata sudo dnf downgrade suricata-<VERSION_BEFORE_8.0.5> sudo dnf versionlock add suricata

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2026-63447?

suricata: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-63447 being exploited?

CVE-2026-63447 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-2026-63447 affect?

CVE-2026-63447 affects suricata. Severity is high (CVSS 7.5). Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. From 8.0.5 until 8.0.6, the FTP parser in src/app-layer-ftp.c can continue allocating transactions after app-layer.protoco

How urgent is CVE-2026-63447?

Priority 44/100. High severity; Remotely exploitable, no login, no user action

Software pages

Suricata and Snort vulnerabilities

Related CVEs

CVE-2026-31931 HIGH 7.5 UPGRADE Suricata is a network IDS, IPS and NSM engine
CVE-2026-31933 HIGH 7.5 UPGRADE Suricata is a network IDS, IPS and NSM engine
CVE-2026-31937 HIGH 7.5 UPGRADE Suricata is a network IDS, IPS and NSM engine
CVE-2026-31932 HIGH 7.5 UPGRADE Suricata is a network IDS, IPS and NSM engine
CVE-2026-31934 HIGH 7.5 UPGRADE Suricata is a network IDS, IPS and NSM engine

References

← Back to latest CVEs