What is CVE-2021-21118?

CVE-2021-21118 is a high-severity vulnerability in Google Chrome, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 8.8/10. Published 2021-02-09.

How severe is CVE-2021-21118?

High severity. CVSS v3 base score is 8.8 out of 10.

Buffer overflow in Google Chrome

CVE-2021-21118

Insufficient data validation in V8 in Google Chrome prior to 88.0.4324.96 allowed a remote attacker to potentially perform out of bounds memory access via a crafted HTML page.

Vulnerability class: Buffer Overflow

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

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.168 (97.0th percentile), scored 2026-10-06.

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 97th percentile — 97.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.168 · newest: 0.168 · change: 0.000

Affected products

Google Chrome — versions unspecified
Microsoft Edge Chromium

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/1161357 (Permissions Required, Third Party Advisory)
msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2021-21118 (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-21118?: CVE-2021-21118 is a high-severity vulnerability in Google Chrome, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 8.8/10. Published 2021-02-09.
How severe is CVE-2021-21118?: High severity. CVSS v3 base score is 8.8 out of 10.