CVE-2026-21925

Vulnerability in the Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition product of Oracle Java SE (component: RMI). Supported versions that are affected are Oracle Java SE: 8u471, 8u471-b50, 8u471-perf, 11.0.29, 17.0.17, 21.0.9, 25.0.1; Oracle GraalVM for JDK: 17.0.17 and 21.0.9; Oracle GraalVM Enterprise Edition: 21.3.16. Difficult to exploit vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition. Successful attacks of this vulnerability can result in unauthorized update, insert or delete access to some of Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition accessible data as well as unauthorized read access to a subset of Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition accessible data. Note: This vulnerability can be exploited by using APIs in the specified Component, e.g., through a web service which supplies data to the APIs. This vulnerability also applies to Java deployments, typically in clients running sandboxed Java Web Start applications or sandboxed Java applets, that load and run untrusted code (e.g., code that comes from the internet) and rely on the Java sandbox for security. CVSS 3.1 Base Score 4.8 (Confidentiality and Integrity impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N).

This vulnerability is rated as Moderate severity for Red Hat because exploitation requires an attacker to occupy an active man-in-the-middle network position, limiting the attack surface to scenarios where network traffic can be intercepted. Java deployments utilizing OpenJDK for Remote Method Invocation (RMI) or JMX communication over encrypted channels are affected when interacting across untrusted networks without server identity verification. Because the flaw only compromises transmitted session data and does not grant direct arbitrary code execution or system-level access, the overall impact is limited to partial loss of confidentiality and integrity.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.