CVE-2024-20921Network attack vector

Unauthenticated access to critical runtime data

Published Feb 17, 2024 · Updated Nov 4, 2025

Information disclosure in Oracle Java SE HotSpot 8u391, 11.0.21, 17.0.9, and 21.0.1 allows remote attackers to read critical data. Oracle identifies HotSpot and API-supplied data as the locus but has not disclosed the operation that mishandles that input. Exploitation requires a difficult condition in a web service that supplies data to HotSpot APIs or a sandboxed client that loads untrusted code; successful attacks expose data accessible to the Java process.

CVSS severity5.9
Medium
EPSS probability0.86%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Oracle Java SE HotSpot 8u391, 11.0.21, 17.0.9, and 21.0.1 allows remote attackers to read critical data. Oracle identifies HotSpot and API-supplied data as the locus but has not disclosed the operation that mishandles that input. Exploitation requires a difficult condition in a web service that supplies data to HotSpot APIs or a sandboxed client that loads untrusted code; successful attacks expose data accessible to the Java process.

The record

CVE
CVE-2024-20921
Published
Feb 17, 2024
Updated
Nov 4, 2025
Vendor
Oracle Corporation
Product
Java Platform, Standard Edition (Java SE)
Classifications
CWE-276, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 17, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 4, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Oracle GraalVM Enterprise Edition:20.3.12
  2. Affected versionversion=Oracle GraalVM Enterprise Edition:21.3.8
  3. Affected versionversion=Oracle GraalVM Enterprise Edition:22.3.4
  4. Affected versionversion=Oracle GraalVM for JDK:17.0.9
  5. Affected versionversion=Oracle GraalVM for JDK:21.0.1
  6. Affected versionversion=Oracle Java SE:11.0.21
  7. Affected versionversion=Oracle Java SE:17.0.9
  8. Affected versionversion=Oracle Java SE:21.0.1
  9. Affected versionversion=Oracle Java SE:8u391
  10. Affected versionversion=Oracle Java SE:8u391-perf

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Oracle Corporation · Java Platform, Standard Edition (Java SE)version=Oracle GraalVM Enterprise Edition:20.3.12; version=Oracle GraalVM Enterprise Edition:21.3.8; version=Oracle GraalVM Enterprise Edition:22.3.4; version=Oracle GraalVM for JDK:17.0.9; version=Oracle GraalVM for JDK:21.0.1; version=Oracle Java SE:11.0.21; version=Oracle Java SE:17.0.9; version=Oracle Java SE:21.0.1; version=Oracle Java SE:8u391; version=Oracle Java SE:8u391-perf

Published CVSS scores

5.9Oracle CorporationCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-276Incorrect Default Permissions
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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