---
id: CVE-2026-70309
title: Microsoft Edge (Chromium-based) Security Feature Bypass Vulnerability
summary: >-
  Origin validation error in Microsoft Edge (Chromium-based) allows an
  unauthorized attacker to bypass a security feature over a network.
severity: medium
cvss: 5.4
cvssVector: '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'
cvssSource: cna
cwe:
  - CWE-346
vendor: Microsoft
product: Microsoft Edge (Chromium-based)
affected:
  - edge_chromium-based >= 1.0.0.0 < 150.0.4078.65
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-08-28T20:14:32.558115Z'
published: '2026-08-28'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T19:39:13.109Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-70309'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70309'
    label: Microsoft Edge (Chromium-based) Security Feature Bypass Vulnerability
tags:
  - cve.org
epss: 0.00212
epssPercentile: 0.10146
ingestedAt: '2026-09-08T19:08:49.646Z'
---

## Overview

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

## Affected

- `edge_chromium-based >= 1.0.0.0 < 150.0.4078.65`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.