Resource exhaustion in Wazuh

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.

CVSS v3 metric

CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H.

Affected products

  • Wazuh — versions >= 3.9.0, < 4.14.5, >= 5.0.0-beta1, < 5.0.0-beta2

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-44253?
CVE-2026-44253 is a medium-severity vulnerability in Wazuh, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 4.9/10. Published 2026-08-19.
How severe is CVE-2026-44253?
Medium severity. CVSS v3 base score is 4.9 out of 10.