Use After Free in Apple macOS

CVE-2026-3777

The application does not properly validate the lifetime and validity of internal view cache pointers after JavaScript changes the document zoom and page state. When a script modifies the zoom property and then triggers a page change, the original view object may be destroyed while stale pointers are still kept and later dereferenced, which under crafted JavaScript and document structures can lead to a use-after-free condition and potentially allow arbitrary code execution.

Vulnerability class: Use-After-Free

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.002 (6.1th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 6th percentile — 6.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-3777: held from 0.001 to 0.002.

EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-3777?
CVE-2026-3777 is a medium-severity vulnerability in Apple macOS, classified under Use After Free. CVSS score: 5.5/10. Published 2026-04-01.
How severe is CVE-2026-3777?
Medium severity. CVSS v3 base score is 5.5 out of 10.