CVE-2026-21947 Cross-site scripting in Oracle Java SE

What is CVE-2026-21947?

CVE-2026-21947 is a low-severity cross-site scripting vulnerability in Oracle Jdk, published on 20 Jan 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

Vulnerability in Oracle Java SE (component: JavaFX). Supported versions that are affected are Oracle Java SE: 8u471-b50. Difficult to exploit vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Oracle Java SE. Successful attacks require human interaction from a person other than the attacker. Successful attacks of this vulnerability can result in unauthorized update, insert or delete access to some of Oracle Java SE accessible data. Note: This vulnerability applies to Java deployments, typically in clients running sandboxed Java Web Start applications or sandboxed Java applets, that load and run untrusted code (e.g., code that comes from the internet) and rely on the Java sandbox for security. This vulnerability does not apply to Java deployments, typically in servers, that load and run only trusted code (e.g., code installed by an administrator). CVSS 3.1 Base Score 3.1 (Integrity impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N).

Weakness: CWE-79

Which versions are affected by CVE-2026-21947?

3 open source packages ship an affected version, including java, java-min and jre. It affects 2 products.

Products include Oracle Jdk, Oracle Jre.

How do I fix CVE-2026-21947?

Upgrade java to a fixed version for your release line: 1.8.0 or 8.0.481.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2026-21947 being exploited?

There is no known exploitation of CVE-2026-21947 in the wild and no public exploit code.

Other vulnerabilities in Oracle Jdk

• CVE-2012-4681 Oracle Java SE Runtime Environment (JRE) Arbitrary Code Execution Exploited Critical 9.8
• CVE-2012-1723 Oracle Java SE Runtime Environment (JRE) Arbitrary Code Execution Exploited Critical 9.8
• CVE-2015-4805 Deserialization in n/a Critical 10.0
• CVE-2015-4835 Other in n/a Critical 10.0
• CVE-2015-4843 Other in n/a Critical 10.0

All Oracle Jdk vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BIT-java-2026-21947, BIT-java-min-2026-21947, BIT-jre-2026-21947, GHSA-998g-2mp2-f264, MINI-4j4g-fhv4-q5ph, UBUNTU-CVE-2026-21947 and 1 more.