How severe is CVE-2021-4118?

CVE-2021-4118 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-4118 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (58th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-4118?

CVE-2021-4118 affects Lightningai Pytorch Lightning. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-4118?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-4118 published?

CVE-2021-4118 was published on 2021-12-23 and last updated on 2026-06-17.

CVE-2021-4118

CVE-2021-4118 is a high-severity vulnerability in Lightningai Pytorch Lightning with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-502.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 6.8
EPSS exploit prediction: 1% (58th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-502
Affected product: Lightningai Pytorch Lightning
Published: 2021-12-23
Last modified: 2026-06-17

Description

pytorch-lightning is vulnerable to Deserialization of Untrusted Data

Frequently asked questions

What is CVE-2021-4118?: pytorch-lightning is vulnerable to Deserialization of Untrusted Data
How severe is CVE-2021-4118?: CVE-2021-4118 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-4118 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (58th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-4118?: CVE-2021-4118 affects Lightningai Pytorch Lightning. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-4118?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-4118 published?: CVE-2021-4118 was published on 2021-12-23 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:lightningai:pytorch_lightning:*:*:*:*:*:python:*:*

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