CVE-2026-25772 in Wazuh
Summary
by MITRE • 03/17/2026
Wazuh is a free and open source platform used for threat prevention, detection, and response. Starting in version 4.4.0 and prior to version 4.14.3, a stack-based buffer overflow vulnerability exists in the Wazuh Database synchronization module (`wdb_delta_event.c`). The SQL query construction logic allows for an integer underflow when calculating the remaining buffer size. This occurs because the code incorrectly aggregates the return value of `snprintf`. If a specific database synchronization payload exceeds the size of the query buffer (2048 bytes), the size calculation wraps around to a massive integer, effectively removing bounds checking for subsequent writes. This allows an attacker to corrupt the stack, leading to a Denial of Service (DoS) or potentially RCE. Version 4.14.3 fixes the issue.
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Analysis
by VulDB Data Team • 03/21/2026
The vulnerability identified as CVE-2026-25772 represents a critical stack-based buffer overflow within the Wazuh database synchronization module, specifically in the wdb_delta_event.c file. This issue affects Wazuh versions 4.4.0 through 4.14.2, creating a significant security risk for organizations relying on this open-source threat detection platform. The vulnerability stems from improper handling of buffer size calculations during SQL query construction, which creates a dangerous condition that can be exploited by malicious actors to compromise system integrity. The flaw is particularly concerning given Wazuh's widespread deployment in security operations centers and its role in critical threat prevention and response workflows.
The technical implementation of this vulnerability involves a specific integer underflow condition that occurs when calculating available buffer space for SQL query construction. The code incorrectly aggregates the return value of snprintf function calls, which leads to a scenario where the calculated remaining buffer size becomes a massive integer due to unsigned integer wraparound. When a specially crafted database synchronization payload exceeds the designated 2048-byte query buffer limit, the size calculation logic fails catastrophically, effectively nullifying all bounds checking mechanisms. This allows subsequent memory writes to occur at arbitrary stack locations, creating a pathway for stack corruption that can be leveraged for system exploitation. The vulnerability aligns with CWE-121 Stack-based Buffer Overflow and CWE-191 Integer Underflow/Overflow, representing a classic example of how improper integer arithmetic can lead to severe memory corruption issues.
The operational impact of this vulnerability extends beyond simple denial of service to potentially enabling remote code execution capabilities, making it a serious concern for security administrators. Attackers can exploit this flaw by crafting malicious database synchronization payloads that trigger the buffer overflow condition, potentially leading to system crashes, unauthorized access, or complete system compromise. The vulnerability affects Wazuh's core database synchronization functionality, which is essential for maintaining consistent security event data across distributed monitoring environments. Organizations using affected versions face significant risk during normal operational procedures, as the vulnerability can be triggered by legitimate synchronization activities or by malicious actors attempting to disrupt security operations. The potential for remote code execution through this vector places this vulnerability in the high-severity category according to industry threat modeling frameworks and aligns with ATT&CK technique T1499.004 for network denial of service attacks.
The remediation for CVE-2026-25772 requires immediate deployment of Wazuh version 4.14.3 or later, which implements proper bounds checking and integer overflow protection in the affected synchronization module. Organizations should conduct thorough vulnerability assessments to identify all systems running affected Wazuh versions and prioritize patching activities accordingly. Security teams should also implement network monitoring to detect potential exploitation attempts and maintain incident response procedures for rapid response to any exploitation activities. The fix addresses the root cause by properly handling the snprintf return value aggregation and implementing robust buffer size calculations that prevent integer underflow conditions. Organizations should verify patch deployment through configuration management systems and conduct regression testing to ensure that the updated synchronization functionality operates correctly without introducing new operational issues. This vulnerability demonstrates the critical importance of proper integer arithmetic handling in security-critical code and serves as a reminder of the need for comprehensive code reviews and security testing in open-source security platforms.