CVE-2026-31221

high

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

https://www.notion.so/CVE-2026-31221-35d1e1393188815f8db7c4fd08076639

https://github.com/Lightning-AI/pytorch-lightning

Details

Source: Mitre, NVD

Published: 2026-05-12

Updated: 2026-05-14

Risk Information

CVSS v2

Base Score: 7.2

Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C

Severity: High

CVSS v3

Base Score: 7.8

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Severity: High

EPSS

EPSS: 0.00061