CVE-2026-44253: DoS (CVSS 4.9)

Description

Wazuh is a free and open source platform used for threat prevention, detection, and response. From 3.9.0 until 4.14.5 and 5.0.0-beta2, the Wazuh cluster protocol in framework/wazuh/core/cluster/common.py allows an authenticated cluster node to exhaust memory on the master. The receive_str() method accepts an attacker-controlled total for InBuffer without a maximum, so a new_str command can request a multi-gigabyte bytearray and repeated requests accumulate in in_str. The divided-message path also retains flag_divided fragments under unique counters in div_msg_box without a count, aggregate-size, or expiration limit. Exploitation can disrupt agent connectivity and alert processing across the monitored environment. This issue is fixed in versions 4.14.5 and 5.0.0-beta2.

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CVSS v3.1 Score

4.9

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0051

Probability of exploitation

0.42%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-770 CWE-770

CWE-789 CWE-789

References

Other References

https://github.com/wazuh/wazuh/commit/d29c5c89a0e16477545ca27f4e06229021e3183c https://github.com/wazuh/wazuh/pull/35173 https://github.com/wazuh/wazuh/releases/tag/v4.14.5 https://github.com/wazuh/wazuh/security/advisories/GHSA-h5r8-gvhv-cmp2 https://github.com/wazuh/wazuh/security/advisories/GHSA-h5r8-gvhv-cmp2

Frequently Asked Questions

What is CVE-2026-44253? +

Wazuh is a free and open source platform used for threat prevention, detection, and response. From 3.9.0 until 4.14.5 and 5.0.0-beta2, the Wazuh cluster protocol in framework/wazuh/core/cluster/common.py allows an authenticated cluster node to exhaust memory on the master. The receive_str() method accepts an attacker-controlled total for InBuffer without a maximum, so a new_str command can request a multi-gigabyte bytearray and repeated requests accumulate in in_str. The divided-message path also retains flag_divided fragments under unique counters in div_msg_box without a count, aggregate-size, or expiration limit. Exploitation can disrupt agent connectivity and alert processing across the monitored environment. This issue is fixed in versions 4.14.5 and 5.0.0-beta2. It has a CVSS v3.1 base score of 4.9 (MEDIUM).

How severe is CVE-2026-44253? +

CVE-2026-44253 has a CVSS v3.1 score of 4.9 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0051, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-44253? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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