SCA: security update for MessagePack (GHSA-hv8m-jj95-wg3x)

high Tenable Cloud Security Plugin ID 443098

Description

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

- MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, A vulnerability exists
in the optional LZ4 decompression path used by MessagePack compression modes Lz4Block and Lz4BlockArray.
The decoder implementation is based on a deprecated fast-decompression algorithm that does not take a
source-length bound. A remote attacker can send a crafted MessagePack payload with manipulated LZ4
token/length fields to force out-of-bounds reads from the compressed input buffer. In affected
environments, this can trigger an AccessViolationException during decompression, causing process
termination (denial of service). Under some conditions, limited unintended memory disclosure from over-
read data may also be possible before failure. This vulnerability is fixed in 2.5.301 and 3.1.7.
(CVE-2026-48109)

Solution

Update the MessagePack library and its related packages to version 2.5.301 or later.

Plugin Details

Severity: High

ID: 443098

Version: Revision 1.5

Type: Local

Family: SCA Checks

Published: 6/12/2026

Updated: 7/6/2026

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

Risk Information

VPR

Risk Factor: Low

Score: 3.5

Percentile: 52.03

Vendor

Vendor Severity: High

CVSS v2

Risk Factor: High

Base Score: 8.5

Temporal Score: 6.3

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

CVSS Score Source: CVE-2026-48109

CVSS v3

Risk Factor: High

Base Score: 8.2

Temporal Score: 7.1

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

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

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 6/11/2026

Vulnerability Publication Date: 6/11/2026

Reference Information

CVE: CVE-2026-48109

cwe: CWE-20

Detections

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