{"id":"CVE-2026-57585","aliases":["GHSA-6v7p-g79w-8964","PYSEC-2026-3625"],"url":"https://o3.security/vulnerability/CVE-2026-57585","summary":"MessagePack: Out-of-bounds read/crash on Unpacker reuse after caught error","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.","published":"2026-06-30T21:36:23.418Z","modified":"2026-08-22T18:50:01.761990778Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.00279,"percentile":0.20478,"asOf":"2026-08-23"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"msgpack","fixedVersion":"1.2.1"}],"fix":{"url":"https://github.com/msgpack/msgpack-python/commit/2c56ddb5d0025ed481d962c0f5d62d19dec7476d","label":"msgpack/msgpack-python@2c56ddb"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/57xxx/CVE-2026-57585.json"},{"type":"ADVISORY","url":"https://github.com/msgpack/msgpack-python/security/advisories/GHSA-6v7p-g79w-8964"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-57585"},{"type":"FIX","url":"https://github.com/msgpack/msgpack-python/commit/2c56ddb5d0025ed481d962c0f5d62d19dec7476d"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-22T18:50:01.761990778Z"}}