PyTorch Lightning allows arbitrary code execution through checkpoint _instantiator hyperparameters
PyTorch Lightning through 2.6.5, fixed in commit d710d68, contains a remote code execution vulnerability in the _load_state function that imports and executes attacker-controlled module names from checkpoint _instantiator hyperparameters. Attackers can craft malicious checkpoint files that bypass weights_only=True protections to execute arbitrary code when LightningModule.load_from_checkpoint is called.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | lightning | < 2.6.6 | 2.6.6 |
| Python (PyPI) | pytorch-lightning | < 2.6.6 | 2.6.6 |
References
- https://github.com/Lightning-AI/pytorch-lightning/issues/21822
- https://github.com/Lightning-AI/pytorch-lightning/commit/d710d689510d50e800f53b3cd773cbca20b1f86f
- https://github.com/Lightning-AI/pytorch-lightning/pull/21832
- https://www.vulncheck.com/advisories/pytorch-lightning-arbitrary-code-execution-via-instantiator-hyperparameter
- https://github.com/Lightning-AI/pytorch-lightning/releases/tag/2.6.6
- https://github.com/advisories/GHSA-qqmf-gpg7-g8gw
- https://nvd.nist.gov/vuln/detail/CVE-2026-58659
- https://github.com/Lightning-AI/pytorch-lightning
- https://github.com/pypa/advisory-database/tree/main/vulns/lightning/PYSEC-2026-3624.yaml
- https://github.com/pypa/advisory-database/tree/main/vulns/pytorch-lightning/PYSEC-2026-3967.yaml
- CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H- Weakness (CWE)
CWE-470- Platform
- Python (PyPI)
- Package
lightning, pytorch-lightning- Disclosed
- 15.07.2026
- Updated
- 11.10.2026 15:18
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2026-3624 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - PYSEC-2026-3967 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-qqmf-gpg7-g8gw - CC BY 4.0
Vulnerability history: pytorch-lightning
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 9
- First → latest
- 12.2021 07.2026
- Without a fix
- 2
- Exploited in attacks
- 0
Severity breakdown
- Critical 5
- High 4
Disclosures per year
- 2021: 1
- 2022: 1
- 2023: 0
- 2024: 2
- 2025: 2
- 2026: 3
-
PyTorch Lightning allows arbitrary code execution through checkpoint _instantiator hyperparameters this entry
Know which vulnerabilities affect your application
With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.