What is CVE-2026-5903?

CVE-2026-5903 is a medium-severity vulnerability in Apple macOS, classified under Protection Mechanism Failure. CVSS score: 6.5/10. Published 2026-04-08.

How severe is CVE-2026-5903?

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

Vulnerability in Apple macOS

CVE-2026-5903

Policy bypass in IFrameSandbox in Google Chrome prior to 147.0.7727.55 allowed a remote attacker who convinced a user to engage in specific UI gestures to bypass navigation restrictions via a crafted HTML page. (Chromium security severity: Low)

Published 2026-04-08 · last modified 2026-07-24.

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 (23.2th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 23.2% 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: +0.001

Affected products

Weakness classification (CWE)

CWE-693 — Protection Mechanism Failure

References

chromereleases.googleblog.com/2026/04/stable-channel-update-for-desktop.html (Release Notes, Vendor Advisory)
issues.chromium.org/issues/483771899 (Permissions Required, Issue Tracking)

Frequently asked questions

What is CVE-2026-5903?: CVE-2026-5903 is a medium-severity vulnerability in Apple macOS, classified under Protection Mechanism Failure. CVSS score: 6.5/10. Published 2026-04-08.
How severe is CVE-2026-5903?: Medium severity. CVSS v3 base score is 6.5 out of 10.