Raw vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:HSummary
CVE-2026-26204 is a medium-severity Buffer Underflow (CWE-124) vulnerability in Wazuh Wazuh. Its CVSS base score is 4.4 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-26259
Vulnerability Data
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.4.1
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and analysis can discover buffer underwrite flaws before deployment but does not stop their introduction.
Security engineering principles require use of safe arithmetic constructs or language features that structurally eliminate integer underflow during subtraction.
Input validation can enforce bounds on indices or pointers before buffer writes, structurally stopping underwrite conditions.
Memory protection mechanisms limit the blast radius of an out-of-bounds write even if the coding flaw exists.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly prevent integer underflow defects via input validation, bounds checking, and static analysis.
Vulnerability identification processes can discover buffer underwrite issues but do not prevent their creation.
Patching removes instances of the weakness after discovery but does not address root-cause prevention in code.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development catches buffer-underflow defects before release.
Secure SDLC mandates input validation and bounds checking that directly prevent buffer underflow.
Application security requirements can specify buffer-size and pointer-safety rules.
Secure architecture and engineering principles require safe memory-handling patterns.
Secure coding standards explicitly forbid unsafe pointer arithmetic and mandate bounds checks.