What is CVE-2026-66798?

CVE-2026-66798 is a medium-severity vulnerability in Microsoft Edge (Chromium-Based), classified under Use After Free. CVSS score: 4.3/10. Published 2026-08-28.

How severe is CVE-2026-66798?

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

Use After Free in Microsoft Edge (Chromium-Based)

CVE-2026-66798

Use after free in Microsoft Edge (Chromium-based) allows an unauthorized attacker to execute code over a network.

Vulnerability class: Use-After-Free

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:N/A:L.

Affected products

Microsoft Edge (Chromium-based)

Weakness classification (CWE)

CWE-416 — Use After Free

References

secure@microsoft.com (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-66798?: CVE-2026-66798 is a medium-severity vulnerability in Microsoft Edge (Chromium-Based), classified under Use After Free. CVSS score: 4.3/10. Published 2026-08-28.
How severe is CVE-2026-66798?: Medium severity. CVSS v3 base score is 4.3 out of 10.