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TI-2026-21195 Aliases CVE-2026-26204

Wazuh: Heap-based NULL WRITE Buffer Underflow in GetAlertData

Priority MEDIUM 58CWE-124Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-191 and the CVSS impact.

Summary

Wazuh is a free and open source platform used for threat prevention, detection, and response. From version 1.0.0 to before version 4.14.4, a heap-based out-of-bounds WRITE occurs in GetAlertData, resulting in writing a NULL byte exactly 1 byte before the start of the buffer allocated by strdup. Due to unsigned integer underflow and pointer arithmetic wrapping, the write lands at offset -1 from the buffer, corrupting heap metadata. A malicious actor can potentially leverage this issue through a compromised agent to cause denial of service or heap corruption by injecting a specially crafted alert into the alerts log file monitored by wazuh-logcollector. This issue has been patched in version 4.14.4.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00169 6th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed wazuh (wazuh): 4.14.4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Wazuhwazuh1.0.0 to before 4.14.44.14.4Patch availableCNA
  • wazuh VendorWazuh Affected 1.0.0 to before 4.14.4 Fixed in 4.14.4 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:wazuh:wazuh:*:*:*:*:*:*:*:*1.0.0 to before 4.14.4VulnerableWazuh
  • cpe:2.3:a:wazuh:wazuh:*:*:*:*:*:*:*:* Versions 1.0.0 to before 4.14.4 Vulnerable ·Wazuh

Remediation

  • Fix · CNA wazuh (wazuh) Fixed in 4.14.4

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-26204

References

Exploit 1

Other 1

  • TI-2025-17783 Remote code execution in Wazuh server KEVCVSS 3.1CRITICAL 9.9
  • TI-2026-23722 Path traversal in wazuh CVSS 3.1CRITICAL 9.9
  • TI-2024-01157 Remote code execution and local privilege escalation in Wazuh Windows agent via NetNTLMv2 hash theft CVSS 4.0CRITICAL 9.5
  • TI-2026-22556 Wazuh: Pre-auth stack-based buffer overflow in wazuh-remoted print_hex_string() due to signed char promotion on x86_64 CVSS 3.1HIGH 8.2
  • TI-2026-35598 Wazuh: cluster peer can read arbitrary master files and forge offline REST API… CVSS 3.1CRITICAL 9.1
  • TI-2026-35467 Wazuh: merged-file header path traversal in cluster sync allows arbitrary file write under WAZUH_PATH in Wazuh manager CVSS 3.1CRITICAL 9.1
See all 72 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences