What is CVE-2026-9930?

CVE-2026-9930 is a medium-severity vulnerability in Apple macOS, classified under Out-of-bounds Write. CVSS score: 4.3/10. Published 2026-05-28.

How severe is CVE-2026-9930?

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

Buffer overflow in Apple macOS

CVE-2026-9930

Out of bounds write in Dawn in Google Chrome on Mac prior to 148.0.7778.216 allowed a remote attacker to perform an out of bounds memory write via a crafted HTML page. (Chromium security severity: High)

Vulnerability class: Buffer Overflow

Published 2026-05-28 · last modified 2026-07-21.

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 (14.2th percentile), scored 2026-10-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 14.2% 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

Apple macOS
Google Chrome — versions 148.0.7778.216

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

chromereleases.googleblog.com/2026/05/stable-channel-update-for-desktop_0877304… (Release Notes)
issues.chromium.org/issues/501499832 (Permissions Required, Vendor Advisory)

Frequently asked questions

What is CVE-2026-9930?: CVE-2026-9930 is a medium-severity vulnerability in Apple macOS, classified under Out-of-bounds Write. CVSS score: 4.3/10. Published 2026-05-28.
How severe is CVE-2026-9930?: Medium severity. CVSS v3 base score is 4.3 out of 10.