CVE-2026-66316: Microsoft Edge (Chromium-based) Spoofing Vulnerability

Overview

Severity

Medium (CVSS 5.4)

CVSS Vector

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

Category

Edge - Chromium

Exploit Status

Not Exploited

Exploitation Likelihood

Unlikely

Patch Tuesday

2026-Jul

Released

2026-07-31

Description

Origin validation error in Microsoft Edge (Chromium-based) allows an unauthorized attacker to perform spoofing over a network.

FAQ

According to the CVSS metrics, successful exploitation of this vulnerability could lead to some loss of confidentiality (C:L), and integrity (I:L) but lead to no loss of availability (A:N). What is the impact of this vulnerability? An attacker who successfully exploited the vulnerability could view some sensitive information (Confidentiality), make changes to disclosed information (Integrity), but cannot limit access to the resource (Availability). According to the CVSS metric, user interaction is required (UI:R). What interaction would the user have to do? The user must visit the attacker‑controlled webpage, and perform the two tap gestures that cause autofill to activate. What is the version information for this release? Microsoft Edge Version Date Released Based on Chromium Version 151.0.4129.59 07/31/2026 151.0.7922.71/.72

Affected Products (1)

Browser

• Microsoft Edge (Chromium-based)

Acknowledgments

Kugelblitz with Microsoft, Kugelblitz with Microsoft

Revision History

• 2026-07-31: Information published.