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CriticalVulnerabilityCVE-2026-114820updated 25 Oct 2026, 17:20 UTC

Java SE and GraalVM JSSE flaw lets remote attackers access data

A weakness in the security code that Java uses for encrypted connections can let an outside attacker read or change data without logging in. Anything running affected Java versions over a network is at risk.

Official, 2 sources
SeverityCriticalCVSS 9.1 of 10
Being exploited?UnclearNo reports either way yet
Fix available?UnclearNo fixed version published in the sources yet
How sure is this?Official, 2 sourcesBacked by an official source

How the attack works simplified

  1. 1Remote attackerNo login or account needed
  2. 2Network requestSent over multiple protocols
  3. 3Java JSSE APIFlawed component processes the input
  4. 4Critical dataRead, changed, or deleted
  5. ResultAttacker reads or changes critical data

What happened

A flaw in the JSSE (Java Secure Socket Extension) component of Oracle Java SE, Oracle GraalVM for JDK, and Oracle GraalVM Enterprise Edition allows unauthenticated network attackers to compromise confidentiality and integrity via APIs exposed through services or untrusted code.

Why it is dangerous: An attacker with network access can create, delete, or modify critical data and gain unauthorized access to data the Java application can reach. Web services that pass data into the affected APIs, and clients running untrusted Java applets or Java Web Start applications, are exposed.

Are you affected?

You are affected if you run Oracle Java SE 8u511 (including perf builds), 11.0.33.0.2, 17.0.21.0.2, 21.0.13.0.2, 25.0.5.0.2, or 27.0.1.0.2, Oracle GraalVM for JDK 17.0.21.0.2 or 21.0.13.0.2, or Oracle GraalVM Enterprise Edition 21.3.20.0.2.

Oracle Java SE: 8u511-b32, 8u511-perf-b32, 11.0.33.0.2, 17.0.21.0.2, 21.0.13.0.2, 25.0.5.0.2, 27.0.1.0.2; Oracle GraalVM for JDK: 17.0.21.0.2, 21.0.13.0.2; Oracle GraalVM Enterprise Edition: 21.3.20.0.2

What to do

  1. Check which Java or GraalVM version your applications run, using 'java -version'
  2. Apply the vendor's Oracle Critical Patch Update or upgrade to a newer release that Oracle lists as fixed
  3. Restrict network exposure of services that pass untrusted data into Java APIs until patched
  4. Disable Java applets and Java Web Start for untrusted content on client machines

Timeline

  1. 24 Oct 2026, 19:17 UTC
    Publicly disclosed
  2. 24 Oct 2026, 19:17 UTC
    Reported by NVD · NVD
  3. 25 Oct 2026, 17:20 UTC
    GitHub Advisory reported on it · GitHub Advisory

Sources 2 reports, oldest first

Official vendor, government CERT or advisory database

Technical details

ID
CVE-2026-114820 · GHSA-255q-pwv4-fjj7
CVSS
9.1 / 10
EPSS
0.3% chance of exploitation within 30 days
Disclosed
24 Oct 2026, 19:17 UTC
On Zero Radar
before the radar started
Last change
25 Oct 2026, 17:20 UTC

The plain-language parts and the attack diagram were written by an AI model (anthropic/claude-haiku-5.5) from the sources above. Facts like versions, exploitation and dates come from the sources themselves. How Zero Radar works

Java SE and GraalVM JSSE flaw lets remote attackers access data · Zero Radar