What is CVE-2026-9891?

CVE-2026-9891 is a critical-severity vulnerability in Apple Macos, classified under Use After Free. CVSS score: 9.0/10. Published 2026-05-28.

How severe is CVE-2026-9891?

Critical severity. CVSS v3 base score is 9.0 out of 10.

Use After Free in Apple Macos

CVE-2026-9891

Use after free in Extensions in Google Chrome prior to 148.0.7778.216 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted Chrome Extension. (Chromium security severity: C…

Vulnerability class: Use-After-Free

EPSS: 0.002 (36.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.0 (Critical). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H.

Affected products

Apple Macos
Google Chrome — versions 148.0.7778.216
Linux Linux_kernel
Microsoft Windows

Weakness classification (CWE)

CWE-416 — Use After Free

References

chrome-cve-admin@google.com (Release Notes, Vendor Advisory)
chrome-cve-admin@google.com (Permissions Required)

Frequently asked questions

What is CVE-2026-9891?: CVE-2026-9891 is a critical-severity vulnerability in Apple Macos, classified under Use After Free. CVSS score: 9.0/10. Published 2026-05-28.
How severe is CVE-2026-9891?: Critical severity. CVSS v3 base score is 9.0 out of 10.