Quick answers
- Is CVE-2026-91464 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-91464 being exploited in the wild.
- How severe is CVE-2026-91464?
- Medium severity, with a CVSS score of 5.3, published 20 October 2026.
- Which products and versions are affected?
- Oracle GraalVM Enterprise Edition 21.3.19.1.1; Oracle Graalvm For Jdk 17.0.20.1, 21.0.12.1; Oracle Java SE 8u503, 11.0.32.1, 17.0.20.1, 21.0.12.1, 25.0.4.1, 27.
- Is there a fix for CVE-2026-91464?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-91464 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-91464?
- Check whether you run Oracle GraalVM Enterprise Edition, Oracle Graalvm For Jdk or Oracle Java SE at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The JGSS component in Oracle Java SE contains a logic flaw that allows network-based exploitation to bypass security restrictions. The vulnerability requires user interaction (such as running an untrusted applet) and has high complexity, but can result in disclosure of confidential data. A complete security update or restricted Java sandbox configuration is required to mitigate this issue.
Affected products
- Oracle Java SE 8u503, 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, 21.0.12.1
- Oracle GraalVM Enterprise Edition 21.3.19.1.1
Timeline
- 2026-10-20: advisory