CVE-2026-70309: CWE-346: Origin Validation Error in Microsoft Microsoft Edge (Chromium-based)

This vulnerability, identified as CWE-346 (Origin Validation Error), exists in Microsoft Edge (Chromium-based) and permits an attacker to bypass a security feature remotely. The issue affects all versions starting from 1.0.0.0 up to version 150.0.4078.65, before the patch was applied. The CVSS 3.1 base score is 5.4, indicating a medium severity level with network attack vector, low attack complexity, no privileges required, user interaction required, and impacts on confidentiality and integrity. Microsoft has published an official fix for this vulnerability.

An attacker can bypass a security feature in Microsoft Edge remotely, potentially leading to limited confidentiality and integrity impacts. There is no indication of availability impact or known exploits in the wild at this time.

An official fix is available from Microsoft. Users and administrators should apply the update to Microsoft Edge version 150.0.4078.65 or later to remediate this vulnerability. Refer to the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70309 for detailed patch information and update instructions.