CVE-2026-41499 PUBLISHED

Wazuh: Multiple Heap-based NULL WRITE Buffer Underflows in parse_uname_string()

Assigner: GitHub_M
Reserved: 20.04.2026 Published: 29.04.2026 Updated: 29.04.2026

Wazuh is a free and open source platform used for threat prevention, detection, and response. From version 4.0.0 to before version 4.14.4, multiple heap-based out-of-bounds WRITE vulnerabilities exist in parse_uname_string() (remoted_op.c). This function processes OS identification data from agents and contains a dangerous code pattern that appears in 4 locations within the same function: writing to strlen(ptr) - 1 without checking for empty strings. When the string is empty, strlen() returns 0, and 0 - 1 wraps to SIZE_MAX due to unsigned integer underflow. Due to pointer arithmetic wrapping, SIZE_MAX effectively becomes -1, causing a write exactly 1 byte before the allocated buffer. This corrupts heap metadata (e.g., the chunk size field in glibc malloc), leading to heap corruption. This issue has been patched in version 4.14.4.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS Score: 6.5

Product Status

Vendor wazuh
Product wazuh
Versions
  • Version >= 4.0.0, < 4.14.4 is affected

References

Problem Types

  • CWE-124: Buffer Underwrite ('Buffer Underflow') CWE
  • CWE-191: Integer Underflow (Wrap or Wraparound) CWE