What is CVE-2026-78947?

CVE-2026-78947 is a medium-severity vulnerability in Google Chrome, classified under Incomplete Cleanup. CVSS score: 6.5/10. Published 2026-08-25.

How severe is CVE-2026-78947?

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

Vulnerability in Google Chrome

CVE-2026-78947

Incomplete cleanup in Chromium in Google Chrome prior to 152.0.7977.65 allowed a remote attacker leveraging social engineering to bypass web origin policy via a crafted Chrome extension. (Chromium security severity: Low)

Published 2026-08-25 · last modified 2026-08-28.

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:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.003 (21.8th percentile), scored 2026-10-10.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 22nd percentile — 21.8% 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-459 — Incomplete Cleanup

References

chromereleases.googleblog.com/2026/08/stable-channel-update-for-desktop_0256176… (Release Notes, Vendor Advisory)
issues.chromium.org/issues/523313378 (Permissions Required)

Frequently asked questions

What is CVE-2026-78947?: CVE-2026-78947 is a medium-severity vulnerability in Google Chrome, classified under Incomplete Cleanup. CVSS score: 6.5/10. Published 2026-08-25.
How severe is CVE-2026-78947?: Medium severity. CVSS v3 base score is 6.5 out of 10.