Oracle GraalVM Enterprise Edition/GraalVM for JDK/Java SE JGSS improper authorization

Summaryinfo

A vulnerability marked as problematic has been reported in Oracle GraalVM Enterprise Edition, GraalVM for JDK and Java SE. Affected is an unknown function of the component JGSS. This manipulation causes improper authorization. This vulnerability is registered as CVE-2026-91463. Remote exploitation of the attack is possible. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in Oracle GraalVM Enterprise Edition, GraalVM for JDK and Java SE (the affected version is unknown). Affected by this vulnerability is an unknown code of the component JGSS. The manipulation with an unknown input leads to a improper authorization vulnerability. The CWE definition for the vulnerability is 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. As an impact it is known to affect confidentiality. The summary by CVE is:

Vulnerability in the Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition product of Oracle Java SE (component: JGSS). Supported versions that are affected are Oracle Java SE: 8u503, 8u503-perf, 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; Oracle GraalVM Enterprise Edition: 21.3.19.1.1. 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 require human interaction from a person other than the attacker. 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, Oracle GraalVM Enterprise Edition accessible data. Note: This vulnerability 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. This vulnerability does not apply to Java deployments, typically in servers, that load and run only trusted code (e.g., code installed by an administrator). CVSS 3.1 Base Score 5.3 (Confidentiality impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N).

The advisory is shared at oracle.com. This vulnerability is known as CVE-2026-91463 since 09/15/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/21/2026). MITRE ATT&CK project uses the attack technique T1548.002 for this issue.

Upgrading eliminates this vulnerability.

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Productinfo

Type

• Programming Language Software

Vendor

• Oracle

Name

• GraalVM Enterprise Edition
• GraalVM for JDK
• Java SE

License

• commercial

Website

• Vendor: https://www.oracle.com

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