Is CVE-2026-91452 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-91452 being exploited in the wild.

How severe is CVE-2026-91452?

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-2026-91452?

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-2026-91452 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-91452?

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.

CVE-2026-91452: Oracle Java SE networking data integrity bypass

CVE-2026-91452 · Severity: medium · CVSS 5.3 · Published 2026-10-20

Oracle Java SE and GraalVM products contain a networking vulnerability that allows unauthenticated attackers to modify data accessed by Java applications. An attacker can supply malicious data to networking APIs to bypass integrity protections and alter information, potentially compromising the confidentiality or consistency of application data without requiring authentication or user interaction.

Technologies: Oracle GraalVM Enterprise Edition, Oracle Graalvm For Jdk, Oracle Java SE. Vendors: Oracle.

Quick answers

Is CVE-2026-91452 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-91452 being exploited in the wild.
How severe is CVE-2026-91452?: 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-2026-91452?: 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-2026-91452 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-91452?: 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 integrity bypass vulnerability in Oracle Java SE's networking component allows unauthenticated attackers with network access to modify data through multiple protocols without prior authentication or user interaction. The vulnerability is exploitable only when untrusted data is supplied directly to APIs in the networking component, not via Java Web Start or applets. Successful exploitation results in unauthorized modification of accessible data.

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

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.