Oracle Java SE/GraalVM for JDK Networking improper authorization

Summaryinfo

A vulnerability classified as problematic was found in Oracle Java SE and GraalVM for JDK. Impacted is an unknown function of the component Networking. Such manipulation leads to improper authorization. This vulnerability is listed as CVE-2026-91394. The attack may be performed from remote. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Oracle Java SE and GraalVM for JDK (version unknown). It has been rated as problematic. Affected by this issue is an unknown function of the component Networking. The manipulation with an unknown input leads to a improper authorization vulnerability. Using CWE to declare the problem leads to CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. Impacted is confidentiality. CVE summarizes:

Vulnerability in the Oracle Java SE, Oracle GraalVM for JDK product of Oracle Java SE (component: Networking). Supported versions that are affected are Oracle Java SE: 11.0.32.1, 17.0.20.1, 21.0.12.1, 25.0.4.1, 27; Oracle GraalVM for JDK: 17.0.20.1 and 21.0.12.1. Difficult to exploit vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Oracle Java SE, Oracle GraalVM for JDK. Successful attacks of this vulnerability can result in unauthorized access to critical data or complete access to all Oracle Java SE, Oracle GraalVM for JDK 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 5.9 (Confidentiality impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N).

The advisory is shared for download at oracle.com. This vulnerability is handled as CVE-2026-91394 since 09/15/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 10/21/2026). The MITRE ATT&CK project declares the attack technique as T1548.002.

Upgrading eliminates this vulnerability.

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Productinfo

Type

• Programming Language Software

Vendor

• Oracle

Name

• GraalVM for JDK
• Java SE

License

• open-source

Website

• Vendor: https://www.oracle.com

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