CVE-2026-44484: PyTorch Lightning malicious code injection in PyPI packages

CVE-2026-44484 · Severity: critical · CVSS 9.8 · Published 2026-05-14

PyTorch Lightning, a popular framework for building AI models, has identified that versions 2.6.2 and 2.6.3 of its software were compromised with malicious code. This code is designed to steal sensitive credentials, such as API keys and access tokens, from systems where the software is installed. Organizations using these versions should immediately rotate all secrets and revert to a safe version to prevent unauthorized access to their infrastructure and data.

Technologies: lightning (PyPI), pytorch-lightning (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2026-44484 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-44484 being exploited in the wild.
How severe is CVE-2026-44484?
Critical severity, with a CVSS score of 9.8, published 14 May 2026.
Which products and versions are affected?
lightning (PyPI) ECOSYSTEM:introduced=2.6.2,fixed=2.6.4; pytorch-lightning (PyPI) ECOSYSTEM:introduced=2.6.2,fixed=2.6.4.
Is there a fix for CVE-2026-44484?
Yes. lightning (PyPI): upgrade to 2.6.4 or later; pytorch-lightning (PyPI): upgrade to 2.6.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-44484 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-44484?
Check whether you run lightning (PyPI) or pytorch-lightning (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • lightning (PyPI): upgrade to 2.6.4 or later
    pip install "lightning>=2.6.4"
  • pytorch-lightning (PyPI): upgrade to 2.6.4 or later
    pip install "pytorch-lightning>=2.6.4"

Technical details

A supply chain compromise affected the PyTorch Lightning package on the Python Package Index (PyPI). Malicious code was embedded in versions 2.6.2 and 2.6.3, categorized as CWE-506 (Embedded Malicious Code). The malicious functionality is designed for credential harvesting, targeting API keys, SSH keys, and access tokens within the environment where the package is executed. The attack vector is network-based as the package is distributed via public repositories, and no specific user interaction or privileges are required beyond installing and running the affected library. The vendor has quarantined the affected versions and recommends pinning to version 2.6.1.

Affected products

  • Lightning-AI pytorch-lightning 2.6.2, 2.6.3

Identifiers

  • CVE-2026-44484
  • GHSA-w37p-236h-pfx3
  • PYSEC-2026-3973
  • PYSEC-2026-508

Timeline

  • 2026-04-30: disclosed: Initial discovery and advisory publication
  • 2026-05-07: advisory: GitHub Advisory published
  • 2026-05-12: other: Advisory last updated
  • 2026-05-14: other: NVD published date

References

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