CVE-2026-44484 — pytorch-lightning
CRITICALCVE-2026-44484 is a critical-severity (CVSS 9.8) CWE-506 vulnerability in pytorch-lightning. No vendor fix is recorded yet; mitigation options are listed below.
Compromise of PyTorch Lightning PyPi Package Versions
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-44484.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-44484 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
pytorch-lightning🐍pytorch-lightningReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
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:
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | pytorch-lightning | all versions | No fix |
| 🐍PyPI | pytorch-lightning | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pytorch-lightning, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of pytorch-lightning has shipped for CVE-2026-44484 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-44484 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-44484. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-44484 in your dependencies?
O3 Security finds CVE-2026-44484 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.