What is CVE-2021-37592?

CVE-2021-37592 is a critical-severity vulnerability in Oisf Suricata, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2021-11-19.

How severe is CVE-2021-37592?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Buffer overflow in Oisf Suricata

CVE-2021-37592

Suricata before 5.0.8 and 6.x before 6.0.4 allows TCP evasion via a client with a crafted TCP/IP stack that can send a certain sequence of segments.

Vulnerability class: Buffer Overflow

Published 2021-11-19 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.016 (74.9th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 75th percentile — 74.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.016 · newest: 0.016 · change: +0.001

Affected products

Oisf Suricata

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

github.com/OISF/suricata/releases (Third Party Advisory, Release Notes)
forum.suricata.io/t/suricata-6-0-4-and-5-0-8-released/1942 (Release Notes, Vendor Advisory)
redmine.openinfosecfoundation.org/issues/4569 (Permissions Required, Third Party Advisory)

Frequently asked questions

What is CVE-2021-37592?: CVE-2021-37592 is a critical-severity vulnerability in Oisf Suricata, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2021-11-19.
How severe is CVE-2021-37592?: Critical severity. CVSS v3 base score is 9.8 out of 10.