Improper Handling of Syntactically Invalid Structure in msgpack5 - #VU152781
Published: September 29, 2026
Vulnerability identifier: #VU152781
CSH Severity: Medium
CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-228
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper handling of syntactically invalid structure in the msgpack5 streaming decoder when processing a decoder stream beginning with the reserved MessagePack byte 0xc1. A remote attacker can supply a stream beginning with 0xc1 followed by additional data to cause a denial of service.
Affected software
msgpack5
Remediation
Install security update from vendor's website.
msgpack5 - update to 6.1.0