What is CVE-2026-66312?

CVE-2026-66312 is a medium-severity vulnerability in Microsoft Edge Chromium, classified under Buffer Over-read. CVSS score: 6.5/10. Published 2026-08-04.

How severe is CVE-2026-66312?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Microsoft Edge Chromium

CVE-2026-66312

Buffer over-read in Microsoft Edge (Chromium-based) allows an authorized attacker to execute code over a network.

EPSS: 0.006 (46.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

Affected products

Microsoft Edge_chromium
Microsoft Edge (Chromium-based) — versions 1.0.0.0

Weakness classification (CWE)

CWE-126 — Buffer Over-read

References

Microsoft Edge (Chromium-based) Remote Code Execution Vulnerability (vendor-advisory, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-66312?: CVE-2026-66312 is a medium-severity vulnerability in Microsoft Edge Chromium, classified under Buffer Over-read. CVSS score: 6.5/10. Published 2026-08-04.
How severe is CVE-2026-66312?: Medium severity. CVSS v3 base score is 6.5 out of 10.