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Fencer Vulns
high 7.8

CVE-2026-58659 json

PyTorch Lightning Arbitrary Code Execution via _instantiator Hyperparameter

published 2026-07-15 3 mo ago modified 2026-11-08 25 h ago also EUVD-2026-44751 , GHSA-qqmf-gpg7-g8gw , PYSEC-2026-3624 , PYSEC-2026-3967

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 50%
public exploits
0
none known

Summary

PyTorch Lightning through 2.6.5, fixed in commit d710d68, contains a remote code execution vulnerability in the _load_state function that imports and executes attacker-controlled module names from checkpoint _instantiator hyperparameters. Attackers can craft malicious checkpoint files that bypass weights_only=True protections to execute arbitrary code when LightningModule.load_from_checkpoint is called.

Patch / fix

  • pypi lightning 2.6.6
  • pypi pytorch-lightning 2.6.6

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-58659 updated cvss 7.8

pytorch-lightning: PyTorch Lightning: Remote code execution via malicious checkpoint files

  • Red Hat AI Inference Server rhaiis/vllm-cpu-rhel9, rhaiis/vllm-tpu-rhel9
    affected: no fix planned “Will not fix”
  • Red Hat AI Inference Server 3.3 rhaiis/vllm-cuda-rhel9 1789582776, rhaiis/vllm-rocm-rhel9 1789504371
    fixed: vendor fix RHSA-2026:68699
  • Red Hat AI Inference Server 3.4 rhaii/vllm-cpu-rhel9 1789681128, rhaii/vllm-cpu-rhel9 1790075793, rhaii/vllm-cuda-rhel9 1789681126, rhaii/vllm-cuda-rhel9 1790090131
    fixed: vendor fix RHSA-2026:69466
  • Red Hat AI Inference Server 3.5 rhaii/vllm-cpu-rhel9 1791473614, rhaii/vllm-cuda-rhel9 1791473631
    fixed: vendor fix RHSA-2026:82415
  • Red Hat Enterprise Linux AI 3.3 rhelai3/bootc-cuda-rhel9 1790866732, rhelai3/bootc-rocm-rhel9 1790791893, rhelai3/bootc-aws-cuda-rhel9 1790936334, rhelai3/bootc-gcp-cuda-rhel9 1790936334, rhelai3/disk-image-cuda-rhel9 1790954179, rhelai3/bootc-azure-cuda-rhel9 1790936351, +1 more
    fixed: vendor fix RHSA-2026:76041
  • Red Hat Enterprise Linux AI 3.4 rhelai3/bootc-cuda-rhel9 1790868254, rhelai3/bootc-aws-cuda-rhel9 1790881122, rhelai3/bootc-gcp-cuda-rhel9 1790881123, rhelai3/disk-image-cuda-rhel9 1790957417, rhelai3/bootc-azure-cuda-rhel9 1790881120
    fixed: vendor fix RHSA-2026:76150
  • Red Hat Enterprise Linux AI 3.5 rhelai3/bootc-cuda-rhel9 1793135861, rhelai3/bootc-aws-cuda-rhel9 1793194817, rhelai3/bootc-gcp-cuda-rhel9 1793194815, rhelai3/disk-image-cuda-rhel9 1793206758, rhelai3/bootc-azure-cuda-rhel9 1793194815
    fixed: vendor fix RHSA-2026:92452
  • Red Hat OpenShift AI 3.4 rhoai/odh-automl-rhel9 1791535789, rhoai/odh-kserve-autogluon-server-rhel9 1791300023
    fixed: vendor fix RHSA-2026:84734
show 3 more
  • Red Hat Enterprise Linux AI 3.4 rhelai3/bootc-rocm-rhel9 1790614447, rhelai3/bootc-azure-rocm-rhel9 1790707552 Red Hat Enterprise Linux AI 3.5 rhelai3/bootc-rocm-rhel9 1793135863, rhelai3/bootc-azure-rocm-rhel9 1793194834
    not affected: vulnerable code not present
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-vllm-gaudi-rhel9
    not affected: component not present
  • Red Hat OpenShift AI 3.4 rhoai/odh-cli-rhel9 1791509689, rhoai/rhai-cli-rhel9 1791509689, rhoai/odh-mlflow-rhel9 1791865967, rhoai/odh-autorag-rhel9 1791557539, rhoai/odh-trainer-rhel9 1791869783, rhoai/odh-eval-hub-rhel9 1791852583, +98 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
3 mo ago

Exploit prediction

0.63% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • vulncheck.com https://www.vulncheck.com/advisories/pytorch-lightning-arbitrary-code-execution-via-instantiator-hyperparameter referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/Lightning-AI/pytorch-lightning/issues/21822 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 8.4 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
GitHub 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CNA 4.0 8.4 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem package affected fixed in
pypi lightning
<2.6.6
2.6.6
pypi pytorch-lightning
<2.6.6
2.6.6

Affected products

  • Lightning-AI pytorch-lightning

Classification

Weakness
  • CWE-470 Use of Externally-Controlled Input to Select Classes or Code

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.