What is CVE-2026-6300?

CVE-2026-6300 is a high-severity vulnerability in Apple macOS, classified under Use After Free. CVSS score: 8.8/10. Published 2026-04-15.

How severe is CVE-2026-6300?

High severity. CVSS v3 base score is 8.8 out of 10.

Is CVE-2026-6300 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Use After Free in Apple macOS

CVE-2026-6300

Use after free in CSS in Google Chrome prior to 147.0.7727.101 allowed a remote attacker to execute arbitrary code inside a sandbox via a crafted HTML page. (Chromium security severity: High)

Vulnerability class: Use-After-Free

Published 2026-04-15 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (33.1th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 33.1% 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: 0.004 · change: +0.001

Affected products

Weakness classification (CWE)

CWE-416 — Use After Free

Public proof-of-concept exploits

notthemystery/CVE-2026-6300-PoC

References

chromereleases.googleblog.com/2026/04/stable-channel-update-for-desktop_15.html (Release Notes, Vendor Advisory)
issues.chromium.org/issues/491994185 (Permissions Required)

Frequently asked questions

What is CVE-2026-6300?: CVE-2026-6300 is a high-severity vulnerability in Apple macOS, classified under Use After Free. CVSS score: 8.8/10. Published 2026-04-15.
How severe is CVE-2026-6300?: High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2026-6300 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.