CVE-2026-31933: Suricata is a network IDS, IPS and NSM engine

Routine

HIGH 7.5REMOTEUPGRADE

CVE-2026-31933 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 IDS, IPS and NSM engine. Prior to versions 7.0.15 and 8.0.4, specially crafted traffic can cause Suricata to slow down, affecting performance in IDS mode. This issue has been patched in versions 7.0.15 and 8.0.4.

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 71%)
CISA exploited list	No
Weakness	CWE-407
Published	2026-04-02
Last modified	2026-10-26

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

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-02 14:16 UTCPublished CVE record published
2026-10-26 21:10 UTCUpdated Record last modified

oisf suricata UPGRADE

Affected: < 7.0.15 · >= 8.0.0 and < 8.0.4

Fixed in: 7.0.15, 8.0.4

Safe to downgrade to: a release before 8.0.0

1. Check installed version

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

2. UPGRADE to 7.0.15 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade suricata

Note

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

3. If no update is available yet, DOWNGRADE to a release before 8.0.0 (Debian / Ubuntu)

apt-cache madison suricata sudo apt install suricata=<VERSION_BEFORE_8.0.0> sudo apt-mark hold suricata

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list suricata sudo dnf downgrade suricata-<VERSION_BEFORE_8.0.0> 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-2026-31933?

suricata: upgrade to 7.0.15, 8.0.4. Exact commands for each OS are on this page.

Is CVE-2026-31933 being exploited?

CVE-2026-31933 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-2026-31933 affect?

CVE-2026-31933 affects suricata. Severity is high (CVSS 7.5). Suricata is a network IDS, IPS and NSM engine. Prior to versions 7.0.15 and 8.0.4, specially crafted traffic can cause Suricata to slow down, affecting performance in IDS mode. This issue has been patched in versions 7.0.15 and 8.0.4.

How urgent is CVE-2026-31933?

Priority 38/100. 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-2026-31937 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
CVE-2026-31935 HIGH 7.5 UPGRADE Suricata is a network IDS, IPS and NSM engine

References

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