CVE-2026-58659Public exploit

Arbitrary code execution via unchecked instantiator import

Published Jul 15, 2026 · Updated Jul 15, 2026

Unsafe reflection in Lightning AI PyTorch Lightning 2.6.5 and earlier allows attackers to execute arbitrary code from a crafted checkpoint. _load_state reads _instantiator from checkpoint hyperparameters, passes its module path to import, resolves the named attribute, and calls it without an allowlist. A user or application must pass the untrusted file to LightningModule.load_from_checkpoint; weights_only=True does not block the application-level import.

CVSS severity8.4
High
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Unsafe reflection in Lightning AI PyTorch Lightning 2.6.5 and earlier allows attackers to execute arbitrary code from a crafted checkpoint. _load_state reads _instantiator from checkpoint hyperparameters, passes its module path to import, resolves the named attribute, and calls it without an allowlist. A user or application must pass the untrusted file to LightningModule.load_from_checkpoint; weights_only=True does not block the application-level import.

The record

CVE
CVE-2026-58659
Published
Jul 15, 2026
Updated
Jul 15, 2026
Vendor
Lightning AI
Product
PyTorch Lightning
Classifications
CWE-470, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=2.6.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Lightning AI · PyTorch Lightningversion=0 <=2.6.5

Published CVSS scores

7.8VulnCheckCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
8.4VulnCheckCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-470Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo