CVE-2026-90473
Severity CVSS v4.0:
MEDIUM
Type:
CWE-190
Integer Overflow or Wraparound
Publication date:
12/09/2026
Last modified:
23/09/2026
Description
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.
Impact
Base Score 4.0
6.90
Severity 4.0
MEDIUM
Base Score 3.x
5.30
Severity 3.x
MEDIUM
References to Advisories, Solutions, and Tools
- https://github.com/msgpack/msgpack-java
- https://github.com/msgpack/msgpack-java/blob/v0.9.12/msgpack-core/src/main/java/org/msgpack/core/MessageUnpacker.java#L573-L581
- https://github.com/msgpack/msgpack-java/issues/1014
- https://www.vulncheck.com/advisories/msgpack-java-through-0.9.12-integer-overflow-via-map32


