What is CVE-2021-41821?

CVE-2021-41821 is a medium-severity vulnerability in Wazuh, classified under Integer Underflow. CVSS score: 6.5/10. Published 2021-09-29.

How severe is CVE-2021-41821?

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

Integer overflow in Wazuh

CVE-2021-41821

Wazuh Manager in Wazuh through 4.1.5 is affected by a remote Integer Underflow vulnerability that might lead to denial of service. A crafted message must be sent from an authenticated agent to the manager.

Published 2021-09-29 · last modified 2026-06-17.

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:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.011 (64.7th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 65th percentile — 64.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000

Affected products

Wazuh

Weakness classification (CWE)

CWE-191 — Integer Underflow

References

documentation.wazuh.com/current/release-notes/release_4_2_0.html (Release Notes, Vendor Advisory)
github.com/wazuh/wazuh/issues/9201 (Exploit, Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2021-41821?: CVE-2021-41821 is a medium-severity vulnerability in Wazuh, classified under Integer Underflow. CVSS score: 6.5/10. Published 2021-09-29.
How severe is CVE-2021-41821?: Medium severity. CVSS v3 base score is 6.5 out of 10.