{"id":"DEBIAN-CVE-2026-114613","details":"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.","modified":"2026-10-23T14:00:14.965107646Z","published":"2026-10-23T13:47:26.732571820Z","upstream":["CVE-2026-114613"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-114613"}],"affected":[{"package":{"name":"python-msgpack","ecosystem":"Debian:12","purl":"pkg:deb/debian/python-msgpack?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.3-2","1.0.3-3","1.1.2-1","1.1.2-2","1.1.2-3","1.1.2-4","1.2.1-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-114613.json"}},{"package":{"name":"python-msgpack","ecosystem":"Debian:13","purl":"pkg:deb/debian/python-msgpack?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.3-3","1.1.2-1","1.1.2-2","1.1.2-3","1.1.2-4","1.2.1-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-114613.json"}},{"package":{"name":"python-msgpack","ecosystem":"Debian:14","purl":"pkg:deb/debian/python-msgpack?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.3-3","1.1.2-1","1.1.2-2","1.1.2-3","1.1.2-4","1.2.1-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-114613.json"}}],"schema_version":"1.9.0"}