What is CVE-2026-83831?

CVE-2026-83831 is a high-severity vulnerability in Microsoft Edge (Chromium-Based), classified under Double Free. CVSS score: 8.8/10. Published 2026-10-27.

How severe is CVE-2026-83831?

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

Double Free in Microsoft Edge (Chromium-Based)

CVE-2026-83831

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

Vulnerability class: Double Free

Published 2026-10-27 · last modified 2026-10-27.

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: 0.008 (55.4th percentile), scored 2026-10-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 55.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

The 30-day trend appears once there are two daily scores.

Affected products

Microsoft Edge (Chromium-Based)

Weakness classification (CWE)

CWE-415 — Double Free

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83831 (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-83831?: CVE-2026-83831 is a high-severity vulnerability in Microsoft Edge (Chromium-Based), classified under Double Free. CVSS score: 8.8/10. Published 2026-10-27.
How severe is CVE-2026-83831?: High severity. CVSS v3 base score is 8.8 out of 10.