CVE-2026-41499 Wazuh: Multiple Heap-based NULL WRITE Buffer Underflows in parse_uname_string()
Attackers can trigger heap corruption via crafted agent data, potentially leading to code execution or service crashes in Wazuh.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-41499?
CVE-2026-41499 is a medium-severity memory corruption vulnerability in Wazuh Wazuh, published on 29 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-41499?
It affects 1 product.
Products include Wazuh Wazuh.
How do I fix CVE-2026-41499?
No fix has been published for CVE-2026-41499 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-41499 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-41499 exists.
Other vulnerabilities in Wazuh Wazuh
- CVE-2025-24016 Wazuh Server Deserialization of Untrusted Data
- CVE-2024-32038 Wazuh Analysis Engine Event Decoder Heap-based Buffer Overflow Remote Code Execution Vulnerability
- CVE-2021-44079 Command injection in n/a
- CVE-2024-1243 Remote code execution and local privilege escalation in Wazuh Windows agent via NetNTLMv2 hash theft
- CVE-2026-61800 Wazuh cluster worker file sync allows arbitrary file write under /var/ossec (incomplete fix for CVE-2026-30893)
Sources
Also known as GHSA-qvqj-p8mm-r7h3.