What is CVE-2026-12457?

CVE-2026-12457 is a medium-severity vulnerability in Apple macOS, classified under Protection Mechanism Failure. CVSS score: 4.2/10. Published 2026-06-17.

How severe is CVE-2026-12457?

Medium severity. CVSS v3 base score is 4.2 out of 10.

Vulnerability in Apple macOS

CVE-2026-12457

Inappropriate implementation in Extensions in Google Chrome prior to 149.0.7827.155 allowed a remote attacker who had compromised the renderer process to bypass site isolation via a crafted HTML page. (Chromium security severity: High)

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

CVSS v3 metric

CVSS v3 base score 4.2 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.001 (2.5th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 3rd percentile — 2.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-693 — Protection Mechanism Failure

References

chromereleases.googleblog.com/2026/06/stable-channel-update-for-desktop_0175051… (Vendor Advisory)
issues.chromium.org/issues/517153117 (Permissions Required)

Frequently asked questions

What is CVE-2026-12457?: CVE-2026-12457 is a medium-severity vulnerability in Apple macOS, classified under Protection Mechanism Failure. CVSS score: 4.2/10. Published 2026-06-17.
How severe is CVE-2026-12457?: Medium severity. CVSS v3 base score is 4.2 out of 10.