CVE-2026-58616

Medium CVSS 4.4

Published 2026-08-28 · last changed 2026-09-11

The fix

Microsoft publishes remediation for this across 1 product branch. The fixed build differs per Windows version, so the row that matters is the one matching the machine you are looking at.

Windows version	Fixed in build	Update	Released
Microsoft Edge for Windows	152.0.4191.52	configuration change	2026-09-20

Having the KB is not the same as knowing whether a machine has it. Windows updates supersede each other, so the update you installed often covers a fix that shipped in an earlier one. Paste your build into the patch checker and it walks that chain for you.

What it is

Concurrent execution using shared resource with improper synchronization ('race condition') in Copilot Chat (Microsoft Edge) allows an authorized attacker to disclose information over a network.

Sources

NVD record for CVE-2026-58616
Microsoft Security Update Guide

CVSS vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N