CVE-2026-85899: Microsoft Edge (Chromium-based) Elevation of Privilege Vulnerability

Overview

Severity

High (CVSS 8.1)

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H/E:P/RL:O/RC:C

Category

Elevation of Privilege

Exploit Status

Not Exploited

Exploitation Likelihood

Unlikely

Patch Tuesday

2026-Oct

Released

2026-10-26

Description

Use after free in Microsoft Edge (Chromium-based) allows an authorized attacker to elevate privileges over a network.

FAQ

What privileges could be gained by an attacker who successfully exploited the vulnerability? An attacker could use this vulnerability to elevate privileges from a Low Integrity Level in a contained ("sandboxed") execution environment to a Medium Integrity Level or a High Integrity Level. Please refer to AppContainer isolation and Mandatory Integrity Control for more information.

Affected Products (1)

Browser

• Microsoft Edge (Chromium-based)

Security Updates (1)

• Release Notes

Acknowledgments

<a href="https://x.com/eternalsakura13">Nan Wang(@eternalsakura13) and Ziling Chen</a>, 0AF3B0CB6FEFDED70267D4510DF654D8, pwn2addr

Revision History

• 2026-10-26: Information published.