What is CVE-2021-21136?

CVE-2021-21136 is a medium-severity vulnerability in Google Android, classified under Origin Validation Error. CVSS score: 6.5/10. Published 2021-02-09.

How severe is CVE-2021-21136?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Google Android

CVE-2021-21136

Insufficient policy enforcement in WebView in Google Chrome on Android prior to 88.0.4324.96 allowed a remote attacker to leak cross-origin data via a crafted HTML page.

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

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.042 (90.6th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 91st percentile — 90.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.042 · newest: 0.042 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-346 — Origin Validation Error

References

chromereleases.googleblog.com/2021/01/stable-channel-update-for-desktop_19.html (Release Notes, Vendor Advisory)
crbug.com/1038002 (Patch, Issue Tracking, Vendor Advisory)
msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2021-21136 (Third Party Advisory)

Frequently asked questions

What is CVE-2021-21136?: CVE-2021-21136 is a medium-severity vulnerability in Google Android, classified under Origin Validation Error. CVSS score: 6.5/10. Published 2021-02-09.
How severe is CVE-2021-21136?: Medium severity. CVSS v3 base score is 6.5 out of 10.