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CVE-2026-21452

MessagePack-Java Vulnerable to Remote Denial of Service via Malicious .msgpack Model File Triggering Unbounded EXT Payload Allocation

Published: Jan 2, 2026Updated: Feb 5, 2026 Sources: CVE List NVD GHSA BDUCWE-400
7.5HIGH
NVD MITRE
EPSS Score
0.6%
Top 55.3%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
Not available

Description

MessagePack for Java Vulnerable to Remote DoS via Malicious EXT Payload Allocation

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
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Weaknesses

CWE-400CWE-789NVD-CWE-Other

Affected Products

msgpack
oss-projectaka msg-pack
messagepackLibrary
OSS Libraries / generic-library
msgpack-javaLibrary
OSS Libraries / generic-library
Maven
package-ecosystem
org.msgpack:msgpack-core
OSS Libraries
Сообщество свободного программного обеспечения
oss-projectaka fsf
msgpackrOn-premLibrary
OSS Libraries / generic-library

Exploitability

Official Patch Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Impact
View detailed technique mapping

References

https://github.com/msgpack/msgpack-java/security/advisories/GHSA-cw39-r4h6-8j3x
github.com
https://nvd.nist.gov/vuln/detail/CVE-2026-21452
nvd.nist.gov
https://github.com/msgpack/msgpack-java/commit/daa2ea6b2f11f500e22c70a22f689f7a9debdeae
github.com
and 2 more references View all →

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