CVE-2025-10769 is a medium severity vulnerability affecting the h2oai h2o-3 product, specifically versions up to and including 3.46.08. The vulnerability arises from insecure deserialization in the H2 JDBC Driver component, within an unknown function related to the /99/ImportSQLTable file. The issue is triggered by manipulation of the 'connection_url' argument, which leads to deserialization of untrusted data. This deserialization flaw can be exploited remotely without requiring user interaction or authentication, as indicated by the CVSS vector (AV:N/AC:L/AT:N/UI:N/PR:L). The vulnerability impacts confidentiality, integrity, and availability to a limited extent (VC:L/VI:L/VA:L). The vendor was notified early but has not responded or provided a patch, and while the exploit has been publicly disclosed, there are no known exploits currently observed in the wild. The vulnerability allows an attacker to potentially execute arbitrary code or cause denial of service by sending crafted input to the vulnerable component, which processes JDBC connection URLs. Given the nature of deserialization vulnerabilities, exploitation could lead to remote code execution or system compromise if the attacker can control the input to the vulnerable function. The vulnerability affects a widely used open-source machine learning platform, h2o-3, which is used for data analysis and predictive modeling, often integrated into enterprise environments.

For European organizations, the impact of CVE-2025-10769 could be significant, especially for those relying on h2o-3 for critical data analytics, machine learning workflows, or business intelligence. Exploitation could lead to unauthorized access to sensitive data, manipulation of analytical results, or disruption of services dependent on the platform. This could affect sectors such as finance, healthcare, manufacturing, and research institutions that leverage AI and data-driven decision-making. The medium severity rating suggests that while the vulnerability is not trivial, it requires some level of privilege (PR:L) to exploit, which may limit exposure to internal threat actors or attackers who have gained some foothold. However, the remote attack vector and lack of required user interaction increase the risk of automated or targeted attacks. The absence of a vendor patch and public exploit disclosure heightens the urgency for organizations to implement mitigations. Failure to address this vulnerability could result in data breaches, loss of data integrity, or service outages, impacting compliance with European data protection regulations such as GDPR.

European organizations should immediately audit their use of h2o-3, specifically checking for versions up to 3.46.08. Since no official patch is available, organizations should consider the following mitigations: 1) Restrict network access to the h2o-3 service, limiting exposure to trusted internal networks and blocking untrusted external traffic to the vulnerable component. 2) Implement strict input validation and sanitization on any user-supplied parameters, especially those related to JDBC connection URLs, to prevent malicious deserialization payloads. 3) Employ runtime application self-protection (RASP) or web application firewalls (WAFs) with custom rules to detect and block suspicious deserialization patterns or anomalous requests targeting the /99/ImportSQLTable endpoint. 4) Monitor logs and network traffic for unusual activity indicative of exploitation attempts, such as unexpected deserialization operations or abnormal JDBC connection strings. 5) Consider isolating the h2o-3 environment in a sandbox or container with minimal privileges to limit potential damage from exploitation. 6) Engage with the vendor or community to track any forthcoming patches or updates and plan for timely application once available. 7) Review and tighten access controls to ensure only authorized users have privileges that could be leveraged for exploitation (noting the PR:L requirement).