What is CVE-2020-8354?

CVE-2020-8354 is a medium-severity vulnerability in Lenovo Bios, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 6.4/10. Published 2020-11-11.

How severe is CVE-2020-8354?

Medium severity. CVSS v3 base score is 6.4 out of 10.

Vulnerability in Lenovo Bios

CVE-2020-8354

A potential vulnerability in the SMI callback function used in the VariableServiceSmm driver in some Lenovo Notebook models may allow arbitrary code execution.

Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)

Published 2020-11-11 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.003 (15.5th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 15.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-367 — Time-of-check Time-of-use (TOCTOU) Race Condition

References

support.lenovo.com/us/en/product_security/LEN-49266 (Vendor Advisory)

Frequently asked questions

What is CVE-2020-8354?: CVE-2020-8354 is a medium-severity vulnerability in Lenovo Bios, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 6.4/10. Published 2020-11-11.
How severe is CVE-2020-8354?: Medium severity. CVSS v3 base score is 6.4 out of 10.