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Full vulnerability report · 2025
CVE-2025-66566High confidence

yawkat LZ4 Java has a possible information leak in Java safe decompressor

yawkat · lz4-java

8.2HighCVSS 4.0
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
Distribution package intelligence

Ubuntu vendor package status

Canonical’s release and source-package findings are shown separately from local repository availability.

1 package state
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Ubuntu releaseSource packageVendor stateFixed versionEvidence
Ubuntu 24.04 LTSnoble · standard archivelz4-javaUnder evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical record ↗Source updated 11 Sept 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2025-66566 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitylz4-java: lz4-java: Information Disclosure via Insufficient Output Buffer Clearing
12 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • lz4-java as a component of Logging Subsystem for Red Hat OpenShift
  • lz4-java as a component of Red Hat build of Apache Camel - HawtIO 4
  • lz4-java as a component of Red Hat build of Apache Camel 4 for Quarkus 3
  • lz4-java as a component of Red Hat build of Apicurio Registry 2
  • lz4-java as a component of Red Hat build of Apicurio Registry 3
  • lz4-java as a component of Red Hat build of Debezium 2
  • lz4-java as a component of Red Hat build of Debezium 3
  • lz4-java as a component of Red Hat Enterprise Linux 8
  • lz4-java-javadoc as a component of Red Hat Enterprise Linux 8
  • lz4-java as a component of Red Hat Fuse 7
  • lz4-java as a component of Red Hat JBoss Enterprise Application Platform Expansion Pack
  • lz4-java as a component of Red Hat Process Automation 7
Summary
A flaw was found in lz4-java. This vulnerability allows disclosure of sensitive data via crafted compressed input due to insufficient clearing of the output buffer in Java-based decompressor implementations.
Remediation
Before applying the update, make sure all previously released errata relevant to your system have been applied. Also, back up your existing installation, including all applications, configuration files, databases and database settings. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2025-201456

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

yawkat LZ4 Java provides LZ4 compression for Java. Insufficient clearing of the output buffer in Java-based decompressor implementations in lz4-java 1.10.0 and earlier allows remote attackers to read previous buffer contents via crafted compressed input. In applications where the output buffer is reused without being cleared, this may lead to disclosure of sensitive data. JNI-based implementations are not affected. This vulnerability is fixed in 1.10.1.

What

yawkat LZ4 Java provides LZ4 compression for Java. Insufficient clearing of the output buffer in Java-based decompressor implementations in lz4-java 1.10.0 and earlier allows remote attackers to read previous buffer contents via crafted compressed input. In applications where the output buffer is reused without being cleared, this may lead to disclosure of sensitive data. JNI-based implementations are not affected. This vulnerability is fixed in 1.10.1.

Why

The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

yawkat LZ4 Java provides LZ4 compression for Java. Insufficient clearing of the output buffer in Java-based decompressor implementations in lz4-java 1.10.0 and earlier allows remote attackers to read previous buffer contents via crafted compressed input. In applications where the output buffer is reused without being cleared, this may lead to disclosure of sensitive data. JNI-based implementations are not affected. This vulnerability is fixed in 1.10.1.

Why

The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Insertion of Sensitive Information Into Sent Data → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-201 ↗

CWE-201: Insertion of Sensitive Information Into Sent Data. The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATPresentAttack requirements: A particular deployment or execution condition must be present.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.VCHighVulnerable-system confidentiality: A successful attack can cause a major loss.VINoneVulnerable-system integrity: No direct loss is represented by this metric.VANoneVulnerable-system availability: No direct loss is represented by this metric.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-201
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2026-2431Oracle SQL Developer: Mehrere Schwachstellen

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Oracle SQL Developer ausnutzen, um die Vertraulichkeit, Integrität und Verfügbarkeit zu gefährden.

Official advisory ↗
BSI · German · WID-SEC-2026-1752IBM Business Automation Workflow: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in IBM Business Automation Workflow ausnutzen, um Sicherheitsvorkehrungen zu umgehen, um einen Denial of Service Angriff durchzuführen, um Informationen offenzulegen, um Dateien zu manipulieren, und um einen Cross-Site Scripting Angriff durchzuführen.

Official advisory ↗
BSI · German · WID-SEC-2026-1204Oracle Financial Services Applications: Mehrere Schwachstellen

Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Oracle Financial Services Applications ausnutzen, um die Vertraulichkeit, Integrität und Verfügbarkeit zu gefährden.

Official advisory ↗
BSI · German · WID-SEC-2026-1194Oracle Communications: Mehrere Schwachstellen

Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Oracle Communications ausnutzen, um die Vertraulichkeit, Integrität und Verfügbarkeit zu gefährden.

Official advisory ↗
BSI · German · WID-SEC-2026-1202Oracle Hyperion: Mehrere Schwachstellen

Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Oracle Hyperion ausnutzen, um die Vertraulichkeit, Integrität und Verfügbarkeit zu gefährden.

Official advisory ↗
BSI · German · WID-SEC-2026-0800LogStash: Schwachstelle ermöglicht Offenlegung von Informationen

Ein entfernter, anonymer Angreifer kann eine Schwachstelle in LogStash ausnutzen, um Informationen offenzulegen.

Official advisory ↗
BSI · German · WID-SEC-2026-0099Elasticsearch: Schwachstelle ermöglicht Offenlegung von Informationen

Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Elasticsearch ausnutzen, um Informationen offenzulegen.

Official advisory ↗
BSI · German · WID-SEC-2026-0019Red Hat Enterprise Linux (Quarkus): Mehrere Schwachstellen

Ein entfernter, authentisierter oder anonymer Angreifer kann mehrere Schwachstellen in Red Hat Enterprise Linux ausnutzen, um einen Cross-Site Scripting Angriff durchzuführen, einen Denial-of-Service-Zustand zu verursachen oder vertrauliche Informationen offenzulegen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20251210Security Bulletin 10 Dec 2025

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 10 Dec 2025, published on 10 December 2025. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0958Multiples vulnérabilités dans les produits IBM

ord?id=CVE-2025-56200 Référence CVE CVE-2025-5889 https://www.cve.org/CVERecord?id=CVE-2025-5889 Référence CVE CVE-2025-59343 https://www.cve.org/CVERecord?id=CVE-2025-59343 Référence CVE CVE-2025-59375 https://www.cve.org/CVERecord?id=CVE-2025-59375 Référence CVE CVE-2025-62718 https://www.cve.org/CVERecord?id=CVE-2025-62718 Référence CVE CVE-2025-64718 https://www.cve.org/CVERecord?id=CVE-2025-64718 Référence CVE CVE-2025-64756 https://www.cve.org/CVERecord?id=CVE-2025-64756 Référence CVE CVE-2025-66168 https://www.cve.org/CVERecord?id=CVE-2025-66168 Référence CVE CVE-2025-66199 https://www.cve.org/CVERecord?id=CVE-2025-66199 Référence CVE CVE-2025-66566 https://www.cve.org/CVERecord?id=CVE-2025-66566 Référence CVE CVE-2025-68160 https://www.cve.org/CVERecord?id=CVE-2025-68160 Référence CVE CVE-2025-68161 https://www.cve.org/CVERecord?id=CVE-2025-68161 Référence CVE CVE-2025-69418 https://www.cve.org/CVERecord?id=CVE-2025-69418 Référence CVE CVE-2025-7338 https://www.cve.org/CVERecord?id=CVE-2025-7338 Référence CVE CVE-2025-7783 https://www.cve.org/CVERecord?id=CVE-2025-7783 Référence CVE CVE-2026-0636 https://www.cve.org/CVERecord?id=CVE-2026-0636 Référence CVE CVE-2026-0994 https://www.cve.org/CVERecord?id=CVE-2026-0994 Référence CVE CVE-2026-10536 https://www.cve.org/CVERecord?id=CVE-2026

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0933Multiples vulnérabilités dans les produits IBM

ecord?id=CVE-2021-23336 Référence CVE CVE-2021-47154 https://www.cve.org/CVERecord?id=CVE-2021-47154 Référence CVE CVE-2024-3651 https://www.cve.org/CVERecord?id=CVE-2024-3651 Référence CVE CVE-2025-11226 https://www.cve.org/CVERecord?id=CVE-2025-11226 Référence CVE CVE-2025-12183 https://www.cve.org/CVERecord?id=CVE-2025-12183 Référence CVE CVE-2025-14813 https://www.cve.org/CVERecord?id=CVE-2025-14813 Référence CVE CVE-2025-5115 https://www.cve.org/CVERecord?id=CVE-2025-5115 Référence CVE CVE-2025-64775 https://www.cve.org/CVERecord?id=CVE-2025-64775 Référence CVE CVE-2025-66168 https://www.cve.org/CVERecord?id=CVE-2025-66168 Référence CVE CVE-2025-66566 https://www.cve.org/CVERecord?id=CVE-2025-66566 Référence CVE CVE-2025-66675 https://www.cve.org/CVERecord?id=CVE-2025-66675 Référence CVE CVE-2025-68161 https://www.cve.org/CVERecord?id=CVE-2025-68161 Référence CVE CVE-2026-0636 https://www.cve.org/CVERecord?id=CVE-2026-0636 Référence CVE CVE-2026-10852 https://www.cve.org/CVERecord?id=CVE-2026-10852 Référence CVE CVE-2026-11383 https://www.cve.org/CVERecord?id=CVE-2026-11383 Référence CVE CVE-2026-11536 https://www.cve.org/CVERecord?id=CVE-2026-11536 Référence CVE CVE-2026-11541 https://www.cve.org/CVERecord?id=CVE-2026-11541 Référence CVE CVE-2026-11594 https://www.cve.org/CVERecord?id=CV

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0627Multiples vulnérabilités dans les produits Splunk

d?id=CVE-2025-64505 Référence CVE CVE-2025-64506 https://www.cve.org/CVERecord?id=CVE-2025-64506 Référence CVE CVE-2025-64720 https://www.cve.org/CVERecord?id=CVE-2025-64720 Référence CVE CVE-2025-65018 https://www.cve.org/CVERecord?id=CVE-2025-65018 Référence CVE CVE-2025-66199 https://www.cve.org/CVERecord?id=CVE-2025-66199 Référence CVE CVE-2025-66293 https://www.cve.org/CVERecord?id=CVE-2025-66293 Référence CVE CVE-2025-66418 https://www.cve.org/CVERecord?id=CVE-2025-66418 Référence CVE CVE-2025-66471 https://www.cve.org/CVERecord?id=CVE-2025-66471 Référence CVE CVE-2025-66516 https://www.cve.org/CVERecord?id=CVE-2025-66516 Référence CVE CVE-2025-66566 https://www.cve.org/CVERecord?id=CVE-2025-66566 Référence CVE CVE-2025-67030 https://www.cve.org/CVERecord?id=CVE-2025-67030 Référence CVE CVE-2025-67735 https://www.cve.org/CVERecord?id=CVE-2025-67735 Référence CVE CVE-2025-68119 https://www.cve.org/CVERecord?id=CVE-2025-68119 Référence CVE CVE-2025-68121 https://www.cve.org/CVERecord?id=CVE-2025-68121 Référence CVE CVE-2025-68156 https://www.cve.org/CVERecord?id=CVE-2025-68156 Référence CVE CVE-2025-68160 https://www.cve.org/CVERecord?id=CVE-2025-68160 Référence CVE CVE-2025-68161 https://www.cve.org/CVERecord?id=CVE-2025-68161 Référence CVE CVE-2025-68384 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0325Multiples vulnérabilités dans les produits Elastic

De multiples vulnérabilités ont été découvertes dans les produits Elastic. Certaines d'entre elles permettent à un attaquant de provoquer une exécution de code arbitraire à distance, une atteinte à la confidentialité des données et un contournement de la politique de sécurité.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0041Multiples vulnérabilités dans les produits Elastic

De multiples vulnérabilités ont été découvertes dans les produits Elastic. Certaines d'entre elles permettent à un attaquant de provoquer un déni de service à distance, une atteinte à la confidentialité des données et une falsification de requêtes côté serveur (SSRF).

Official advisory ↗
NCSC-NL · Dutch · NCSC-2026-0021Kwetsbaarheden verholpen in Oracle Database Server producten

Multiple vulnerabilities in lz4-java (1.10.0 and earlier) and Oracle Essbase (21.8.0.0.0) allow unauthorized access and sensitive data disclosure due to insufficient buffer clearing and unauthenticated access, respectively.

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Fixed
Action
Before applying the update, make sure all previously released errata relevant to your system have been applied. Also, back up your existing installation, including all applications, configuration files, databases and database settings. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 5 Dec 2025 · Last source change 5 Dec 2025, 18:27 UTC · CWE-201 · Insertion of Sensitive Information Into Sent Data

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2025-201456
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD not scheduled

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2025-201456↗Vendor CSAF · Red Hat Product Security↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2025-66566 · cve.blacktree.nl