CVEvulnerability

CVE-2026-114613

7.5 HIGH Published 2026-10-22 Modified 2026-10-23 Official page ↗
Status
Awaiting Analysis
Published
2026-10-22
Last modified
2026-10-23
Assigner
[email protected]
CVSS 3.1 ([email protected])
7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weaknesses
CWE-401

Description

MessagePack is the serializer implementation for Python msgpack.org. Prior to 1.2.3, the msgpack-python C extension (msgpack._cmsgpack) leaks a decoded map value when deserialization rejects a key with strict_map_key=True (the default). Repeated malformed inputs can cause unbounded process memory growth and denial of service in applications that deserialize attacker-controlled MessagePack data. Both unpackb() and the streaming Unpacker API are affected. The pure-Python fallback does not exhibit this leak in the reported tests. This issue is fixed in version 1.2.3.

Related

Weakness · CWE (1)

  • CWE-401 Missing Release of Memory after Effective Lifetime weakness

References