Summary
Security Advisory: Compromise of PyTorch Lightning PyPI Package Versions
Published: 2026-04-30
Last Updated: 2026-05-12
Github Advisory: CVE-2026-44484
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:
2.6.22.6.3
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:
Impact
CVE-2026-44484 has a CVSS score of 9.8 (Critical). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-44484? CVE-2026-44484 is a critical-severity security vulnerability in pytorch-lightning (pip), affecting versions = 2.6.2. No fixed version is listed yet.
- How severe is CVE-2026-44484? CVE-2026-44484 has a CVSS score of 9.8 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of pytorch-lightning are affected by CVE-2026-44484? pytorch-lightning (pip) versions = 2.6.2 is affected.
- Is there a fix for CVE-2026-44484? No fixed version is listed for CVE-2026-44484 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2026-44484 exploitable, and should I be worried? Whether CVE-2026-44484 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-44484 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.