Msgpack Python vulnerabilities
2 vulnerabilities
Known vulnerabilities in Msgpack Python, newest first, with CVSS severity, EPSS, KEV listings, ransomware use and the affected versions.
PrioritiseCVE-2026-114613msgpack · msgpack-python +169 moreMessagePack: Unbounded memory leak in msgpack C extension on strict_map_key validation failureMessagePack 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.CVSS7.5HighEPSS0.54%PrioritiseCVE-2026-57585msgpack · msgpack-python +26 moreMessagePack: Out-of-bounds read/crash on Unpacker reuse after caught errorMessagePack is the serializer implementation for Python msgpack.org. Prior to 1.2.1, there is an Out-of-bounds read/crash on Unpacker reuse after a caught error, potentially leading to a DoS attack. If the Unpacker is used repeatedly after an error occurs, the process may crash with a SEGV. This issue has been fixed in version 1.2.1.CVSS7.5HighEPSS0.49%