{"id":"PYSEC-2026-3625","details":"MessagePack 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.","aliases":["CVE-2026-57585","GHSA-6v7p-g79w-8964"],"modified":"2026-08-07T09:45:03.571724402Z","published":"2026-06-30T22:16:57.837Z","references":[{"type":"ADVISORY","url":"https://github.com/msgpack/msgpack-python/security/advisories/GHSA-6v7p-g79w-8964"},{"type":"FIX","url":"https://github.com/msgpack/msgpack-python/commit/2c56ddb5d0025ed481d962c0f5d62d19dec7476d"}],"affected":[{"package":{"name":"msgpack","ecosystem":"PyPI","purl":"pkg:pypi/msgpack"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.2.1"}]}],"versions":["0.5.0","0.5.1","0.5.2","0.5.3","0.5.4","0.5.5","0.5.6","0.6.0","0.6.1","0.6.2","1.0.0","1.0.0rc1","1.0.1","1.0.2","1.0.3","1.0.3rc1","1.0.4","1.0.4rc1","1.0.5","1.0.5rc1","1.0.6","1.0.6rc1","1.0.7","1.0.8","1.1.0","1.1.0rc1","1.1.0rc2","1.1.1","1.1.1rc1","1.1.2","1.2.0","1.2.0rc1"],"ecosystem_specific":{},"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/msgpack/PYSEC-2026-3625.yaml"}}],"schema_version":"1.8.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}