CVE-2026-21452
MessagePack-Java Vulnerable to Remote Denial of Service via Malicious .msgpack Model File Triggering Unbounded EXT Payload Allocation
No known exploitation. EPSS puts it in the 48th percentile. Fixed in 0.9.11.
What to do
Find your product and version, then upgrade to the build on the right.
- Msgpack-javaAffected: < 0.9.11Upgrade to: not statedStated by: CVE record
- Maven org.msgpack:msgpack-coreAffected: < 0.9.11Upgrade to: 0.9.11Stated by: GitHub advisory
- Сообщество свободного программного обеспечения msgpackrAffected: до 0.9.10 включительноUpgrade to: not statedStated by: BDU
Versions as the sources state them. Full version matrix after sign-in
What it is
From the CVE record
MessagePack for Java Vulnerable to Remote DoS via Malicious EXT Payload Allocation
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.6% chance of exploitation activity in the next 30 days, which ranks it in the 48th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
5 events over 34 days, from the signal feeds we watch.
- Patch availablerecord updated
- Publishedweakness classified, att&ck mapped
Affected products
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Scored 7.5 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required NoneNo authentication required — anyone can exploit this
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality NoneNo confidentiality impact
- Integrity NoneNo integrity impact
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
Sources
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