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ZDI-26-528: Wazuh Cluster DAPI Protocol Deserialization of Untrusted Data Remote Code Execution Vulnerability

AI summary · glm-5.3

ZDI advisory ZDI-26-528 discloses CVE-2026-28220, a CVSS 9.9 deserialization RCE in Wazuh's cluster DAPI protocol exploitable by network-adjacent attackers.

Wazuh contains a deserialization-of-untrusted-data flaw in its cluster DAPI protocol, tracked as CVE-2026-28220 with CVSS 9.9. Network-adjacent attackers can execute arbitrary code on affected installations, but must first obtain the ability to execute low-privileged code on a worker node. The vulnerability was disclosed through ZDI advisory ZDI-26-528.

  • Deserialization flaw in Wazuh cluster DAPI protocol, CVE-2026-28220, CVSS 9.9
  • Network-adjacent RCE requires prior low-privileged code execution on a worker node
  • Wazuh is widely deployed open-source security monitoring platform

Vulnerabilities mentionedAll →

CVEVulnerabilityCVSSEPSSFlagsAffectedExposurePublished
CVE-2026-28220
Wazuh is a free and open source platform used for threat prevention, detection, and response.

Wazuh is a free and open source platform used for threat prevention, detection, and response. Prior to version 4.14.5, issues in the Cluster Distributed API (DAPI) handling allow a cluster peer, or any actor able to authenticate to the cluster channel using the shared cluster key, to make the master node deserialize an attacker-controlled callable and execute it under an attacker-controlled RBAC context. The cluster code in `framework/wazuh/core/cluster/common.py` deserializes JSON with `as_wazuh_object()`, which resolves any callable whose top-level package is wazuh or api (an overly broad allowlist controlled only by `ALLOWED_CALLABLES_PACKAGES`), and DAPI requests handled in framework/wazuh/core/cluster/dapi/dapi.py accept a client-supplied rbac_permissions value that `run_local()` applies as the global RBAC context, so supplying an rbac_mode of black causes authorization checks for expose_resources-protected functions to pass without any legitimate permission assignment. Combined, these allow privileged administrative actions on the master node such as arbitrary file writes under WAZUH_PATH, creation of new API users, and tampering with security.yaml, and can be chained into full manager compromise. This issue has been fixed in version 4.14.5.

NVD description · AI analysis pending
9.1<1% PoC
  • wazuh wazuh
Full article

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of Wazuh. An attacker must first obtain the ability to execute low-privileged code on a worker node in order to exploit this vulnerability. The ZDI has assigned a CVSS rating of 9.9. The following CVEs are assigned: CVE-2026-28220.

This source does not provide full text. Read it at zerodayinitiative.com.