Vulnerabilities
Vulnerable Software

Vulnerability Details CVE-2026-48109

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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.003
EPSS Ranking 21.1%
CVSS Severity
CVSS v3 Score 8.2
Products affected by CVE-2026-48109


Contact Us

Shodan ® - All rights reserved