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SCA: security update for org.msgpack:msgpack-core (GHSA-cw39-r4h6-8j3x)

high Tenable Cloud Security Plugin ID 436569

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

 - MessagePack for Java is a serializer implementation for Java. A denial-of-service vulnerability exists in
 versions prior to 0.9.11 when deserializing .msgpack files containing EXT32 objects with attacker-
 controlled payload lengths. While MessagePack-Java parses extension headers lazily, it later trusts the
 declared EXT payload length when materializing the extension data. When ExtensionValue.getData() is
 invoked, the library attempts to allocate a byte array of the declared length without enforcing any upper
 bound. A malicious .msgpack file of only a few bytes can therefore trigger unbounded heap allocation,
 resulting in JVM heap exhaustion, process termination, or service unavailability. This vulnerability is
 triggered during model loading / deserialization, making it a model format vulnerability suitable for
 remote exploitation. The vulnerability enables a remote denial-of-service attack against applications that
 deserialize untrusted .msgpack model files using MessagePack for Java. A specially crafted but
 syntactically valid .msgpack file containing an EXT32 object with an attacker-controlled, excessively
 large payload length can trigger unbounded memory allocation during deserialization. When the model file
 is loaded, the library trusts the declared length metadata and attempts to allocate a byte array of that
 size, leading to rapid heap exhaustion, excessive garbage collection, or immediate JVM termination with an
 OutOfMemoryError. The attack requires no malformed bytes, user interaction, or elevated privileges and can
 be exploited remotely in real-world environments such as model registries, inference services, CI/CD
 pipelines, and cloud-based model hosting platforms that accept or fetch .msgpack artifacts. Because the
 malicious file is extremely small yet valid, it can bypass basic validation and scanning mechanisms,
 resulting in complete service unavailability and potential cascading failures in production systems.
 Version 0.9.11 fixes the vulnerability. (CVE-2026-21452)

See Also

https://github.com/advisories/GHSA-cw39-r4h6-8j3x

Plugin Details

Severity: High

ID: 436569

Version: Revision 1.5

Type: Local

Family: SCA Checks

Published: 1/5/2026

Updated: 7/2/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.73

Vendor

Vendor Severity: High

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.1

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

CVSS Score Source: CVE-2026-21452

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.7

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 1/5/2026

Vulnerability Publication Date: 1/2/2026

Reference Information

CVE: CVE-2026-21452