CVE-2026-66318: Microsoft Edge (Chromium-based) Information Disclosure Vulnerability

Overview

Severity
High (CVSS 8.1)
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/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 disclose information over a network.

FAQ

What type of information could be disclosed by this vulnerability? The type of information that could be disclosed if an attacker successfully exploited this vulnerability is sensitive information. How could an attacker exploit this vulnerability? An attacker could attempt to trick a user into interacting with a malicious request that appears legitimate. When the user approves the request, the attacker could cause the app to obtain an access token on the user’s behalf and send it to a location controlled by the attacker, without the user being clearly informed about what access is being granted. 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.