PYSEC-2026-3972

    Dashboard / Vulnerabilities / PYSEC-2026-3972

    PYSEC-2026-3972

    Published: 10 Sept 2026Last Modified: 10 Sept 2026

    Summary: PyTorch Lightning load_from_checkpoint has an insecure checkpoint deserialization

    Details: 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://nvd.nist.gov/vuln/detail/CVE-2026-31221, https://github.com/Lightning-AI/pytorch-lightning, https://www.notion.so/CVE-2026-31221-35d1e1393188815f8db7c4fd08076639, https://pypi.org/project/pytorch-lightning, https://github.com/advisories/GHSA-75m9-98v2-hjpm

    Affected packages

    Package

    Name: lightning

    Purl: pkg:pypi/lightning

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -None

    Affected versions

    0.0.2

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High