CVE-2026-31221

HIGH CVSS 3.1: 7.8 EPSS 0.39%
Updated Jun 17, 2026
Lightningai
Parameter Value
CVSS 7.8 (HIGH)
Affected Versions before 2.6.0
Type CWE-502 (Deserialization of Untrusted Data)
Vendor Lightningai
Public PoC No

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.

Attack Parameters

Attack Vector
Local
Requires local access
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
Required
User action required

Impact Assessment

Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service

CVSS Vector v3.1

Vulnerable Products 1

Configuration From (including) Up to (excluding)
Lightningai Pytorch_Lightning
cpe:2.3:a:lightningai:pytorch_lightning:*:*:*:*:*:python:*:*
<= 2.6.0