CVE-2025-12051 is a vulnerability classified under CWE-787 (Out-of-bounds Write) found in Insyde Software's InsydeH2O tools, which are commonly used in firmware development and management. The root cause is the use of the RTL_QUERY_REGISTRY_DIRECT flag by drivers within these tool packages to read registry values. This approach allows an untrusted user-mode application to influence the registry data being read, potentially causing a buffer overflow due to insufficient bounds checking. The overflow occurs because the driver does not properly validate the size or content of the registry data before copying it into a fixed-size buffer, leading to memory corruption. Exploiting this vulnerability can result in arbitrary code execution at the kernel level, allowing an attacker to escalate privileges, compromise system integrity, and disrupt availability. The CVSS v3.1 score of 7.8 indicates a high severity, with attack vector local (AV:L), low attack complexity (AC:L), requiring low privileges (PR:L), no user interaction (UI:N), unchanged scope (S:U), and high impact on confidentiality (C:H), integrity (I:H), and availability (A:H). Although no public exploits are known at this time, the vulnerability poses a significant risk due to its potential impact and ease of exploitation by local attackers. The affected versions are not explicitly listed but are implied to be those using vulnerable InsydeH2O tool drivers. The vulnerability was reserved in late 2025 and published in early 2026, indicating recent discovery and disclosure.

For European organizations, this vulnerability presents a critical risk particularly to those involved in hardware manufacturing, firmware development, and IT environments where InsydeH2O tools are deployed. Successful exploitation can lead to full system compromise, including unauthorized access to sensitive data, disruption of critical services, and potential lateral movement within networks. The local attack vector means that attackers need some level of access, but given the low privilege requirement, insider threats or malware with limited rights could exploit this flaw to escalate privileges. This is especially concerning for sectors such as telecommunications, manufacturing, and critical infrastructure, where firmware integrity is paramount. The high impact on confidentiality, integrity, and availability could lead to data breaches, operational downtime, and loss of trust. Additionally, the lack of known exploits currently provides a window for proactive mitigation, but also means organizations must be vigilant for emerging threats. The vulnerability could also affect supply chain security if compromised firmware tools are used in device production or maintenance.

Organizations should immediately inventory their use of InsydeH2O tools and identify affected versions once detailed version information and patches are released by Insyde Software. Until patches are available, implement strict access controls to limit local user access to systems running these tools, especially restricting untrusted or low-privilege users from interacting with the registry or driver components involved. Employ application whitelisting and endpoint detection to monitor for suspicious activity indicative of exploitation attempts. Firmware and driver integrity checks should be enforced to detect unauthorized modifications. Additionally, organizations should isolate critical systems using network segmentation to reduce the risk of lateral movement. Regularly update and audit system permissions to minimize the attack surface. Security teams should monitor threat intelligence sources for any emerging exploit code or proof-of-concept releases. Finally, prepare incident response plans tailored to potential kernel-level compromises to ensure rapid containment and recovery.