# CVE-2026-91379: Oracle Java SE integrity vulnerability in JDK tools

Source: https://junglewise.ai/threats/cve-2026-91379-vulnerability-in-the-oracle-java-se-oracle-graalvm-for-jdk-oracle  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-20. Updated: 2026-10-20  
License: CC BY 4.0 with a link back

CVE-2026-91379 · Severity: medium · CVSS 4.7 · Published 2026-10-20

Oracle Java SE and GraalVM contain an integrity vulnerability in JDK tools that affects Java deployments running untrusted code in sandboxed environments. An unauthenticated attacker with local access could exploit this with user interaction to create, delete, or modify critical data. This vulnerability does not affect server deployments running only trusted code.

Technologies: [Oracle GraalVM Enterprise Edition](https://junglewise.ai/threats/technologies/graalvm-enterprise-edition), [Oracle Graalvm For Jdk](https://junglewise.ai/threats/technologies/graalvm-for-jdk), [Oracle Java SE](https://junglewise.ai/threats/technologies/java-se). Vendors: [Oracle](https://junglewise.ai/threats/vendors/oracle).

## Quick answers

**Is CVE-2026-91379 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-91379 being exploited in the wild.

**How severe is CVE-2026-91379?** Medium severity, with a CVSS score of 4.7, 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-perf, 11.0.32.1, 17.0.20.1, 21.0.12.1, 25.0.4.1, 27.

**Is there a fix for CVE-2026-91379?** 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-2026-91379 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-91379?** 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 integrity vulnerability in JDK tools (component unspecified in summary) requires local access and user interaction from a different user. The attack vector is local, and successful exploitation results in unauthorized modification, creation, or deletion of data accessible to the Java process. Patches are available from Oracle.

## Affected products

- Oracle Java SE 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

## References

- [https://www.oracle.com/security-alerts/cpuoct2026.html](https://www.oracle.com/security-alerts/cpuoct2026.html)

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