What is CVE-2026-8563?

CVE-2026-8563 is a medium-severity vulnerability in Google Chrome, classified under Protection Mechanism Failure. CVSS score: 4.3/10. Published 2026-05-14.

How severe is CVE-2026-8563?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Vulnerability in Google Chrome

CVE-2026-8563

Insufficient policy enforcement in IFrame Sandbox in Google Chrome on Windows prior to 148.0.7778.168 allowed a remote attacker to bypass navigation restrictions via a crafted HTML page. (Chromium security severity: Medium)

Published 2026-05-14 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (12.8th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 12.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.001

Affected products

Google Chrome — versions 148.0.7778.168
Microsoft Windows

Weakness classification (CWE)

CWE-693 — Protection Mechanism Failure

References

chromereleases.googleblog.com/2026/05/stable-channel-update-for-desktop_12.html (Vendor Advisory)
issues.chromium.org/issues/40061220 (Permissions Required)

Frequently asked questions

What is CVE-2026-8563?: CVE-2026-8563 is a medium-severity vulnerability in Google Chrome, classified under Protection Mechanism Failure. CVSS score: 4.3/10. Published 2026-05-14.
How severe is CVE-2026-8563?: Medium severity. CVSS v3 base score is 4.3 out of 10.