# CVE-2026-91374: Oracle Java SE data access vulnerability in Serviceability

Source: https://junglewise.ai/threats/cve-2026-91374-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-2026-91374 · Severity: medium · CVSS 4.8 · Published 2026-10-20

A vulnerability in Oracle Java SE and related products allows a network attacker to read and modify sensitive data without authentication. The flaw affects the Serviceability component, which Java applications depend on for runtime management and monitoring. An attacker could exploit this through APIs or web services to gain unauthorized access to data or alter information.

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-2026-91374 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-91374 being exploited in the wild.

**How severe is CVE-2026-91374?** Medium severity, with a CVSS score of 4.8, 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-2026-91374?** 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-2026-91374 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-91374?** 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

An unauthenticated network vulnerability in the Serviceability component of Oracle Java SE allows attackers to achieve unauthorized read and write access to accessible data. The attack requires difficult conditions (high attack complexity) but no user interaction or privileges. Exploitation is possible through APIs in the affected component, including sandboxed Java Web Start applications and applets that process untrusted code.

## 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

## References

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

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