{"api_version":"1","generated_at":"2026-05-13T07:42:00+00:00","cve":"CVE-2026-31221","urls":{"html":"https://cve.report/CVE-2026-31221","api":"https://cve.report/api/cve/CVE-2026-31221.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-31221","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-31221"},"summary":{"title":"CVE-2026-31221","description":"PyTorch-Lightning versions 2.6.0 and earlier contain an insecure deserialization vulnerability (CWE-502) in the checkpoint loading mechanism. The LightningModule.load_from_checkpoint() method, which is commonly used to load saved model states, internally calls torch.load() without setting the security-restrictive weights_only=True parameter. This default behavior allows the deserialization of arbitrary Python objects via the Pickle module. A remote attacker can exploit this by providing a maliciously crafted checkpoint file, leading to arbitrary code execution on the victim's system when the file is loaded.","state":"PUBLISHED","assigner":"mitre","published_at":"2026-05-12 16:16:14","updated_at":"2026-05-12 16:38:07"},"problem_types":["n/a"],"metrics":[],"references":[{"url":"https://www.notion.so/CVE-2026-31221-35d1e1393188815f8db7c4fd08076639","name":"https://www.notion.so/CVE-2026-31221-35d1e1393188815f8db7c4fd08076639","refsource":"cve@mitre.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/Lightning-AI/pytorch-lightning","name":"https://github.com/Lightning-AI/pytorch-lightning","refsource":"cve@mitre.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-31221","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31221","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"n/a","product":"n/a","version":"affected n/a","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"product":"n/a","vendor":"n/a","versions":[{"status":"affected","version":"n/a"}]}],"descriptions":[{"lang":"en","value":"PyTorch-Lightning versions 2.6.0 and earlier contain an insecure deserialization vulnerability (CWE-502) in the checkpoint loading mechanism. The LightningModule.load_from_checkpoint() method, which is commonly used to load saved model states, internally calls torch.load() without setting the security-restrictive weights_only=True parameter. This default behavior allows the deserialization of arbitrary Python objects via the Pickle module. A remote attacker can exploit this by providing a maliciously crafted checkpoint file, leading to arbitrary code execution on the victim's system when the file is loaded."}],"problemTypes":[{"descriptions":[{"description":"n/a","lang":"en","type":"text"}]}],"providerMetadata":{"dateUpdated":"2026-05-12T15:09:17.157Z","orgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","shortName":"mitre"},"references":[{"url":"https://github.com/Lightning-AI/pytorch-lightning"},{"url":"https://www.notion.so/CVE-2026-31221-35d1e1393188815f8db7c4fd08076639"}]}},"cveMetadata":{"assignerOrgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","assignerShortName":"mitre","cveId":"CVE-2026-31221","datePublished":"2026-05-12T00:00:00.000Z","dateReserved":"2026-03-09T00:00:00.000Z","dateUpdated":"2026-05-12T15:09:17.157Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-12 16:16:14","lastModifiedDate":"2026-05-12 16:38:07","problem_types":["n/a"],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"31221","Ordinal":"1","Title":"CVE-2026-31221","CVE":"CVE-2026-31221","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"31221","Ordinal":"1","NoteData":"PyTorch-Lightning versions 2.6.0 and earlier contain an insecure deserialization vulnerability (CWE-502) in the checkpoint loading mechanism. The LightningModule.load_from_checkpoint() method, which is commonly used to load saved model states, internally calls torch.load() without setting the security-restrictive weights_only=True parameter. This default behavior allows the deserialization of arbitrary Python objects via the Pickle module. A remote attacker can exploit this by providing a maliciously crafted checkpoint file, leading to arbitrary code execution on the victim's system when the file is loaded.","Type":"Description","Title":"CVE-2026-31221"}]}}}