{"id":"PYSEC-2026-4021","details":"MONAI before 1.5.2 contains a deserialization of untrusted data vulnerability in the algo_from_pickle function in monai/auto3dseg/utils.py. The function reads a .pkl file and passes its contents to pickle.loads without validating the data source or content. If an application invokes algo_from_pickle on an attacker-supplied pickle file, an object defining __reduce__ is executed during deserialization, resulting in arbitrary code execution in the context of the application.","aliases":["CVE-2026-100846","GHSA-89gg-p5r5-q6r4"],"modified":"2026-10-01T09:15:05.348272565Z","published":"2026-09-27T02:17:23.283Z","references":[{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/monai-before-1.5.2-remote-code-execution-via-pickle-deserialization"},{"type":"EVIDENCE","url":"https://github.com/Project-MONAI/MONAI/security/advisories/GHSA-89gg-p5r5-q6r4"}],"affected":[{"package":{"name":"monai","ecosystem":"PyPI","purl":"pkg:pypi/monai"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.5.2"}]}],"versions":["0.0.1","0.1.0","0.2.0","0.3.0","0.4.0","0.5.0","0.5.1","0.5.2","0.5.3","0.6.0","0.7.0","0.8.0","0.8.1","0.9.0","0.9.1","1.0.0","1.0.1","1.1.0","1.2.0","1.3.0","1.3.1","1.3.2","1.3.2rc1","1.3.3rc1","1.4.0","1.4.0rc1","1.4.0rc10","1.4.0rc11","1.4.0rc12","1.4.0rc2","1.4.0rc3","1.4.0rc4","1.4.0rc5","1.4.0rc6","1.4.0rc7","1.4.0rc8","1.4.0rc9","1.4.1rc1","1.5.0","1.5.0rc1","1.5.1","1.5.2rc1"],"ecosystem_specific":{},"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/monai/PYSEC-2026-4021.yaml"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"}]}