PT-2026-40060 · Pypi · Pytorch-Lightning

Published 2026-05-12 · Updated 2026-05-12 · CVE-2026-31221

Positive Technologies (AI Summary)

CVSS v3.1

8.8

High

Base vector

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

Name of the Vulnerable Software and Affected Versions PyTorch-Lightning versions 2.6.0 and earlier

Description An insecure deserialization issue exists in the checkpoint loading mechanism. The load from checkpoint() function in LightningModule internally calls torch.load() without the weights only=True parameter. This allows the deserialization of arbitrary Python objects via the Pickle module, which is a process of converting a byte stream back into an object. A remote attacker can provide a maliciously crafted checkpoint file to achieve arbitrary code execution on the system when the file is loaded.

Recommendations Update PyTorch-Lightning to a version later than 2.6.0. As a temporary workaround, avoid loading checkpoint files from untrusted sources using the load from checkpoint() function.

Exploit

Fix

Deserialization of Untrusted Data

Weakness Enumeration

CWE-502

Related Identifiers

CVE-2026-31221

GHSA-75M9-98V2-HJPM

Affected Products

Pytorch-Lightning

References · 7

• 🔥 https://notion.so/CVE-2026-31221-35d1e1393188815f8db7c4fd08076639 · Exploit
• https://cve.org/CVERecord?id=CVE-2026-31221 · Security Note
• https://osv.dev/vulnerability/GHSA-75m9-98v2-hjpm · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-31221 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-31221 · Security Note
• https://ubuntu.com/security/CVE-2026-31221 · Vendor Advisory
• https://github.com/Lightning-AI/pytorch-lightning · Note