What is CVE-2026-87466?

CVE-2026-87466 is a medium-severity vulnerability in Google Chrome, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2026-09-09.

How severe is CVE-2026-87466?

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

Auth bypass in Google Chrome

CVE-2026-87466

Incorrect authorization in Workers in Google Chrome prior to 153.0.8010.36 allowed a remote attacker to bypass web origin policy via a crafted HTML page. (Chromium security severity: Medium)

Vulnerability class: Broken Access Control

Published 2026-09-09 · last modified 2026-09-09.

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:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.003 (18.5th percentile), scored 2026-10-24.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 19th percentile — 18.5% 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

Google Chrome

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

chromereleases.googleblog.com/2026/09/stable-channel-update-for-desktop_0808145… (Release Notes, Vendor Advisory)
issues.chromium.org/issues/500467033 (Permissions Required)

Frequently asked questions

What is CVE-2026-87466?: CVE-2026-87466 is a medium-severity vulnerability in Google Chrome, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2026-09-09.
How severe is CVE-2026-87466?: Medium severity. CVSS v3 base score is 4.3 out of 10.