Quick answers
- Is CVE-2026-91463 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-91463 being exploited in the wild.
- How severe is CVE-2026-91463?
- 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, 8u503-perf, 11.0.32.1, 17.0.20.1, 21.0.12.1, 25.0.4.1, 27.
- Is there a fix for CVE-2026-91463?
- 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-2026-91463 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-91463?
- 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
A difficult-to-exploit vulnerability in the Java Generic Security Service (JGSS) component affects multiple Java SE releases and GraalVM distributions. The vulnerability requires network access and user interaction (human-initiated action) to trigger. Successful exploitation results in unauthorized read access to sensitive data accessible to the Java process, without integrity compromise or availability impact.
Affected products
- 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, 21.0.12.1
- Oracle GraalVM Enterprise Edition 21.3.19.1.1
Timeline
- 2026-10-20: disclosed