CVE-2026-90473 MEDIUM

CVE-2026-90473: msgpack-java through 0.9.12 Integer Overflow via MAP32

Vendor Msgpack
Product msgpack-java
Weakness CWE-190
Published September 12, 2026
Last update September 12, 2026

CVSS base score

6.9/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality —
Integrity —

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

What the vulnerability does

01Description

msgpack-java through 0.9.12 contains an integer overflow vulnerability in MessageUnpacker.skipValue() when processing MAP32 containers with large element counts. Attackers can supply a MAP32 element count at or above 0x40000000 that wraps when doubled, causing the parser cursor to desynchronize and attacker-controlled data to be returned in place of later fields.

Key dates

02Disclosure timeline

September 12, 2026 CVE published