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.
History

Tue, 12 May 2026 19:30:00 +0000

Type Values Removed Values Added
First Time appeared Lightningai
Lightningai pytorch Lightning
Vendors & Products Lightningai
Lightningai pytorch Lightning

Tue, 12 May 2026 17:45:00 +0000

Type Values Removed Values Added
Title Insecure Deserialization in PyTorch-Lightning Allows Arbitrary Code Execution

Tue, 12 May 2026 16:00:00 +0000

Type Values Removed Values Added
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.
References

cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-05-12T15:09:17.157Z

Reserved: 2026-03-09T00:00:00.000Z

Link: CVE-2026-31221

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-05-12T16:16:14.020

Modified: 2026-05-12T16:38:07.807

Link: CVE-2026-31221

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-12T19:15:22Z