What is CVE-2021-21140?

CVE-2021-21140 is a medium-severity vulnerability in Google Chrome, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 6.8/10. Published 2021-02-09.

How severe is CVE-2021-21140?

Medium severity. CVSS v3 base score is 6.8 out of 10.

Buffer overflow in Google Chrome

CVE-2021-21140

Uninitialized use in USB in Google Chrome prior to 88.0.4324.96 allowed a local attacker to potentially perform out of bounds memory access via via a USB device.

Vulnerability class: Buffer Overflow

Published 2021-02-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.008 (53.7th percentile), scored 2026-10-06.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 54th percentile — 53.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Google Chrome — versions unspecified
Microsoft Edge

Weakness classification (CWE)

CWE-119 — Improper Restriction of Operations within the Bounds of a Memory Buffer

References

chromereleases.googleblog.com/2021/01/stable-channel-update-for-desktop_19.html (Release Notes, Vendor Advisory)
crbug.com/1136327 (Permissions Required, Third Party Advisory)
msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2021-21140 (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2021-21140?: CVE-2021-21140 is a medium-severity vulnerability in Google Chrome, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 6.8/10. Published 2021-02-09.
How severe is CVE-2021-21140?: Medium severity. CVSS v3 base score is 6.8 out of 10.