CVE-2026-44484: Pytorch lightning Compromise Of PyTorch Lightning PyPi Vulnerability

CRITICAL
Advisory Identifier: GHSA-w37p-236h-pfx3
CVSS 9.8
CWE-506
Published
Advisory Summary

CVE-2026-44484 is a CRITICAL (CVSS 9.8) compromise of pytorch lightning pypi vulnerability (CWE-506: Embedded Malicious Code) affecting Pytorch lightning libraries in the PyPI ecosystem. The issue involves compromise of pytorch lightning pypi package versions. Remediation is available in the latest vendor maintenance releases.

CVE-2026-44484 at a Glance

CVE Identifier CVE-2026-44484
GHSA Identifier GHSA-w37p-236h-pfx3
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-506: Embedded Malicious Code
Affected Product Pytorch lightning
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 9.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-44484

To remediate this vulnerability, upgrade all affected Pytorch lightning dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

pytorch-lightning fixed: Latest secure release
pip install pytorch-lightning>=Latest secure release
pytorch-lightning fixed: Latest secure release
pip install pytorch-lightning>=Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

pip show pytorch-lightning

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-44484, inspect your installed packages using pip:

pip show pytorch-lightning

Analyze the terminal output to locate any version of Pytorch lightning in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The pip show pytorch-lightning command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-506: Embedded Malicious Code, where the product contains code that appears to be malicious in nature. In Pytorch lightning, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

# Security Advisory: Compromise of PyTorch Lightning PyPI Package Versions **Published:** 2026-04-30 **Last Updated:** 2026-05-12 **Github Advisory:** [CVE-2026-44484](https://github.com/advisories/GHSA-w37p-236h-pfx3) We have identified a security incident affecting certain versions of one of our PyPI packages. ## What happened We have determined that one or more released versions of this package have been compromised and include malicious code. Our current investigation indicates that the affected versions have introduced functionality consistent with a credential harvesting mechanism. We are still actively analysing the scope and behaviour of the code. At this stage, the root cause of the compromise is still under investigation. ## What versions are affected We are currently working to confirm the exact set of impacted versions. We have determined the following versions as affected and ask that you delete them from your systems: - `2.6.2` - `2.6.3` We will update this advisory if the versions impacted by this vulnerability change. ## What you should do immediately If you have installed or are running any potentially affected versions: - Assume the environment may be compromised - Immediately rotate all credentials and secrets that may have been exposed, including: - API keys - Access tokens - SSH keys - Service account credentials - Rebuild affected systems from a known clean state - Pin PyTorch Lightning to version `2.6.1` - Review logs for any suspicious or unauthorised activity ## Actions we have taken - Quarantined malicious versions from PyPI - Recommend using version `2.6.1`: https://github.com/Lightning-AI/pytorch-lightning/releases/tag/2.6.1 - Revoked and rotated all internal credentials associated with our release process - Initiated a full investigation into the compromise ## Ongoing investigation We are actively working to: - Identify the exact mechanism of compromise - Confirm the full set of affected versions - Determine the behaviour and impact of the malicious code - Assess any downstream impact to users We will provide updates as soon as more information becomes available. ## Commitment to transparency We take the security of our users and the integrity of our software supply chain extremely seriously. We will continue to share timely and accurate updates as our investigation progresses. ## Contact If you have questions or believe you may be impacted, please contact us at: **security@lightning.ai**

CVE-2026-44484 Affected Pytorch lightning Versions

2 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
pytorch-lightning
PyPI
2.6.2
All 1 versions
2.6.2
None specified
pytorch-lightning
PyPI
2.6.3
All 1 versions
2.6.3
None specified

References

Frequently Asked Questions

What is CVE-2026-44484?
CVE-2026-44484 is a security vulnerability in Pytorch lightning involving Compromise of PyTorch Lightning PyPi Package Versions under CWE-506: Embedded Malicious Code.
Which Pytorch lightning versions are affected?
Affected versions include releases prior to current release patches across affected packages: pytorch-lightning.
What version fixes CVE-2026-44484?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is pytorch-lightning affected?
Yes, pytorch-lightning is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2026-44484?
CVE-2026-44484 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-44484?
CVE-2026-44484 is classified under CWE-506: Embedded Malicious Code (The product contains code that appears to be malicious in nature.).
How can I check PyPI dependencies for CVE-2026-44484?
Run the dependency tree command: 'pip show pytorch-lightning'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-w37p-236h-pfx3",
  "modified" : "2026-06-08T23:12:39Z",
  "published" : "2026-05-07T00:52:55Z",
  "aliases" : [ "CVE-2026-44484" ],
  "summary" : "Compromise of PyTorch Lightning PyPi Package Versions",
  "details" : "# Security Advisory: Compromise of PyTorch Lightning PyPI Package Versions\n\n**Published:** 2026-04-30  \n**Last Updated:** 2026-05-12 \n\n**Github Advisory:** [CVE-2026-44484](https://github.com/advisories/GHSA-w37p-236h-pfx3)\n\nWe have identified a security incident affecting certain versions of one of our PyPI packages.\n\n## What happened\n\nWe have determined that one or more released versions of this package have been compromised and include malicious code.\n\nOur current investigation indicates that the affected versions have introduced functionality consistent with a credential harvesting mechanism. We are still actively analysing the scope and behaviour of the code.\n\nAt this stage, the root cause of the compromise is still under investigation.\n\n## What versions are affected\n\nWe are currently working to confirm the exact set of impacted versions.\n\nWe have determined the following versions as affected and ask that you delete them from your systems:\n\n- `2.6.2`\n- `2.6.3`\n\nWe will update this advisory if the versions impacted by this vulnerability change.\n\n## What you should do immediately\n\nIf you have installed or are running any potentially affected versions:\n\n- Assume the environment may be compromised  \n- Immediately rotate all credentials and secrets that may have been exposed, including:  \n  - API keys  \n  - Access tokens  \n  - SSH keys  \n  - Service account credentials  \n- Rebuild affected systems from a known clean state  \n- Pin PyTorch Lightning to version `2.6.1`  \n- Review logs for any suspicious or unauthorised activity  \n\n## Actions we have taken\n\n- Quarantined malicious versions from PyPI  \n- Recommend using version `2.6.1`: https://github.com/Lightning-AI/pytorch-lightning/releases/tag/2.6.1  \n- Revoked and rotated all internal credentials associated with our release process  \n- Initiated a full investigation into the compromise  \n\n## Ongoing investigation\n\nWe are actively working to:\n\n- Identify the exact mechanism of compromise  \n- Confirm the full set of affected versions  \n- Determine the behaviour and impact of the malicious code  \n- Assess any downstream impact to users  \n\nWe will provide updates as soon as more information becomes available.\n\n## Commitment to transparency\n\nWe take the security of our users and the integrity of our software supply chain extremely seriously.\n\nWe will continue to share timely and accurate updates as our investigation progresses.\n\n## Contact\n\nIf you have questions or believe you may be impacted, please contact us at:\n\n**security@lightning.ai**",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "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"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "pytorch-lightning"
    },
    "versions" : [ "2.6.2" ]
  }, {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "pytorch-lightning"
    },
    "versions" : [ "2.6.3" ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/Lightning-AI/pytorch-lightning/security/advisories/GHSA-w37p-236h-pfx3"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-44484"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/Lightning-AI/pytorch-lightning"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-506" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-07T00:52:55Z",
    "nvd_published_at" : "2026-05-14T15:16:48Z"
  }
}