CVE-2026-57977 Microsoft CVE debrief

Who should care

Users of Microsoft Edge (Chromium-based) should apply patches immediately to prevent potential spoofing attacks. This includes administrators and users who utilize Microsoft Edge (Chromium-based) for browsing. The vulnerability allows unauthorized attackers to perform spoofing over a network, which could lead to phishing or other malicious activities.

Technical summary

The vulnerability has a CVSS score of 7.1 and is classified as HIGH severity. It exists in the Microsoft Edge (Chromium-based) browser and allows an unauthorized attacker to perform spoofing over a network by improper neutralization of input during web page generation. This vulnerability is also known as cross-site scripting. Users should verify their systems and apply patches provided by Microsoft.

Defensive priority

High priority, apply patches immediately and monitor for suspicious activity

Recommended defensive actions

• Apply patches provided by Microsoft
• Ensure Microsoft Edge (Chromium-based) is updated to the latest version
• Monitor for suspicious activity
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE record was published on 2026-07-03T21:17:01.193Z and was last modified on 2026-07-07T13:14:18.280Z. The NVD entry is currently Analyzed. This information is based on the NVD entry and the CVE record. The vulnerability affects Microsoft Edge (Chromium-based) and allows an unauthorized attacker to perform spoofing over a network by improper neutralization of input during web page generation. The CVSS score is 7.1, classified as HIGH severity. Users should verify their systems and apply patches provided by Microsoft.

Official resources