CVE-2026-31221

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.

CVSS v3 7.8 HIGH

7.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/Lightning-AI/pytorch-lightning	Product
https://www.notion.so/CVE-2026-31221-35d1e1393188815f8db7c4fd08076639	Exploit Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:lightningai:pytorch_lightning:*:*:*:*:*:python:*:*

History

14 May 2026, 18:54

Type	Values Removed	Values Added
CWE		CWE-502
First Time		Lightningai Lightningai pytorch Lightning
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 7.8
References	~~() https://github.com/Lightning-AI/pytorch-lightning -~~	() https://github.com/Lightning-AI/pytorch-lightning - Product
References	~~() https://www.notion.so/CVE-2026-31221-35d1e1393188815f8db7c4fd08076639 -~~	() https://www.notion.so/CVE-2026-31221-35d1e1393188815f8db7c4fd08076639 - Exploit, Third Party Advisory
CPE		cpe:2.3:a:lightningai:pytorch_lightning::::::python::*

12 May 2026, 16:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-05-12 16:16

Updated : 2026-05-15 19:16

NVD link : CVE-2026-31221

Mitre link : CVE-2026-31221

CVE.ORG link : CVE-2026-31221

JSON object : View

Products Affected

lightningai

pytorch_lightning

CWE

CWE-502

Deserialization of Untrusted Data

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