# CVE-2026-91395: Oracle Java SE data integrity and denial of service in Utility

Source: https://junglewise.ai/threats/cve-2026-91395-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-2026-91395 · Severity: medium · CVSS 6.5 · Published 2026-10-20

Oracle Java SE, GraalVM for JDK, and GraalVM Enterprise Edition contain a vulnerability in a utility component that can be exploited remotely without authentication. An attacker can modify or delete sensitive data and cause service interruptions in applications using the affected Java versions. This affects both server deployments and client-side Java applications that run untrusted 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-2026-91395 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-91395 being exploited in the wild.

**How severe is CVE-2026-91395?** Medium severity, with a CVSS score of 6.5, 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.

**Is there a fix for CVE-2026-91395?** 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-2026-91395 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-91395?** 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 vulnerability is in the Utility component of Oracle Java SE and related products and is easily exploitable via network protocols without requiring authentication, credentials, or user interaction. Successful exploitation allows an attacker to gain unauthorized data modification/deletion access and trigger partial denial of service. The flaw can be leveraged through APIs in the Utility component, including in web services that process untrusted data, and affects Java applets and Web Start deployments in sandboxed environments.

## Affected products

- Oracle Java SE 8u503, 8u503-perf, 11.0.32.1
- 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

## References

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

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