CVE-2025-30761 is a vulnerability in the Scripting component of Oracle Java SE and Oracle GraalVM Enterprise Edition that stems from unsafe deserialization of untrusted data (CWE-502). This vulnerability allows an unauthenticated attacker with network access to exploit APIs exposed over multiple protocols to manipulate critical data within the affected Java environments. The affected versions include Oracle Java SE 8u451, 8u451-perf, and 11.0.27, as well as GraalVM Enterprise Edition 21.3.14. The attack vector is network-based with no required privileges or user interaction, but the attack complexity is high, making exploitation challenging. The vulnerability can be triggered through web services that supply data to the vulnerable APIs or through sandboxed Java Web Start applications or applets that load untrusted code relying on the Java sandbox for security. Successful exploitation results in unauthorized creation, deletion, or modification of data, impacting the integrity of the system. Although no known exploits are currently reported in the wild, the vulnerability poses a significant risk due to the widespread use of Oracle Java SE and GraalVM in enterprise environments. The CVSS 3.1 score of 5.9 reflects a medium severity with a focus on integrity impact, no confidentiality or availability impact, and no requirement for privileges or user interaction. This vulnerability highlights the risks associated with unsafe deserialization and the importance of validating and sanitizing input data in Java applications.

For European organizations, this vulnerability poses a moderate risk primarily to the integrity of critical data managed or processed by Oracle Java SE and GraalVM Enterprise Edition environments. Given the extensive use of Oracle Java SE in enterprise applications, financial services, government systems, and critical infrastructure across Europe, unauthorized modification or deletion of data could disrupt business operations, lead to data corruption, or cause compliance violations under regulations such as GDPR. The integrity impact could affect transaction records, configuration data, or application logic, potentially leading to financial loss, reputational damage, or operational downtime. The difficulty of exploitation reduces immediate risk, but the lack of required authentication and user interaction means that exposed network services could be targeted by skilled attackers. Organizations relying on sandboxed Java applications that load untrusted code are particularly vulnerable, as these environments may be exploited to bypass security controls. The absence of known exploits in the wild provides a window for proactive mitigation, but the medium severity rating necessitates timely attention to prevent potential compromise.

European organizations should implement the following specific mitigations: 1) Identify and inventory all Oracle Java SE and GraalVM Enterprise Edition deployments, focusing on versions 8u451, 8u451-perf, 11.0.27, and GraalVM 21.3.14. 2) Restrict network access to Java APIs and services that process untrusted data, employing network segmentation and firewall rules to limit exposure. 3) Disable or restrict the use of Java Web Start applications and sandboxed applets that load untrusted code, or migrate to more secure deployment models. 4) Implement strict input validation and sanitization on all data supplied to vulnerable APIs, especially in web services, to prevent unsafe deserialization attacks. 5) Monitor logs and network traffic for anomalous activity targeting Java scripting components or unusual API calls. 6) Apply Oracle security advisories promptly once patches become available, and test updates in controlled environments before deployment. 7) Employ runtime application self-protection (RASP) or similar technologies to detect and block exploitation attempts in real-time. 8) Educate developers and administrators about the risks of unsafe deserialization and secure coding practices to prevent similar vulnerabilities. These targeted actions go beyond generic advice by focusing on the specific attack vectors and deployment scenarios relevant to this vulnerability.