CVE-2025-30761 is a vulnerability affecting Oracle Java SE and Oracle GraalVM Enterprise Edition, specifically within the Scripting component. The affected versions include Oracle Java SE 8u451, 8u451-perf, and 11.0.27, as well as GraalVM Enterprise Edition 21.3.14. This vulnerability allows an unauthenticated attacker with network access to exploit multiple protocols to compromise the affected Java environments. The exploitation vector involves the use of APIs in the Scripting component, such as those exposed by web services that supply data to these APIs. Additionally, this vulnerability impacts Java deployments that run sandboxed Java Web Start applications or sandboxed Java applets which load and execute untrusted code, relying on the Java sandbox for security. The root cause is related to CWE-502, which involves deserialization of untrusted data, potentially leading to unauthorized code execution or manipulation of critical data. Successful exploitation can result in unauthorized creation, deletion, or modification of critical data accessible by Oracle Java SE or GraalVM Enterprise Edition. The CVSS 3.1 base score is 5.9, indicating a medium severity level, with the vector indicating network attack vector (AV:N), high attack complexity (AC:H), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), no confidentiality impact (C:N), high integrity impact (I:H), and no availability impact (A:N). The vulnerability is considered difficult to exploit due to the high attack complexity, but it does not require authentication or user interaction, increasing the risk surface for exposed systems. No known exploits are currently reported in the wild, and no official patches have been linked yet, emphasizing the need for proactive mitigation and monitoring.

For European organizations, the impact of CVE-2025-30761 can be significant, especially for those relying heavily on Oracle Java SE and GraalVM Enterprise Edition in their enterprise applications, middleware, or cloud environments. The vulnerability allows unauthorized modification of critical data, which can lead to data integrity breaches, manipulation of business logic, or corruption of application state. This could disrupt business operations, cause financial loss, or damage reputation. Since the vulnerability affects sandboxed Java Web Start applications and applets that load untrusted code, organizations using legacy Java client applications or web services that integrate with external or third-party data sources are particularly at risk. The lack of confidentiality impact reduces the risk of data leakage but does not mitigate the serious consequences of data tampering. The medium severity score reflects the balance between the difficulty of exploitation and the potential damage. However, given the widespread use of Java in European financial institutions, government agencies, and critical infrastructure sectors, even a medium severity vulnerability can have outsized consequences if exploited. The absence of known exploits in the wild currently provides a window for remediation but should not lead to complacency.

1. Immediate assessment of all Oracle Java SE and GraalVM Enterprise Edition deployments to identify affected versions (8u451, 8u451-perf, 11.0.27, and GraalVM 21.3.14). 2. Restrict network access to Java services exposing the vulnerable Scripting APIs, especially those accessible via multiple protocols, by implementing strict firewall rules and network segmentation. 3. Disable or restrict the use of Java Web Start applications and sandboxed applets that load untrusted code, or migrate to more secure application delivery mechanisms. 4. Implement input validation and sanitization on all data supplied to the vulnerable APIs to prevent exploitation via malicious payloads. 5. Monitor network traffic and application logs for unusual API calls or data manipulation attempts targeting the Scripting component. 6. Stay updated with Oracle’s security advisories for official patches or workarounds and apply them promptly once available. 7. Consider deploying runtime application self-protection (RASP) or endpoint detection and response (EDR) solutions capable of detecting anomalous behavior related to Java scripting components. 8. Conduct security awareness training for developers and system administrators about the risks of deserialization vulnerabilities and secure coding practices to prevent similar issues.