---
id: CVE-2026-66311
title: Microsoft Edge (Chromium-based) Tampering Vulnerability
summary: >-
  Missing authorization in Microsoft Edge (Chromium-based) allows an
  unauthorized attacker to perform tampering locally.
severity: medium
cvss: 6.2
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C'
cvssSource: cna
cwe:
  - CWE-862
vendor: Microsoft
product: Microsoft Edge (Chromium-based)
affected:
  - edge_chromium-based >= 1.0.0.0 < 151.0.4129.59
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-08-04T14:19:46.424821Z'
published: '2026-08-03'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T18:25:32.842Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-66311'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66311'
    label: Microsoft Edge (Chromium-based) Tampering Vulnerability
tags:
  - cve.org
epss: 0.00405
epssPercentile: 0.32025
ingestedAt: '2026-09-08T17:06:31.894Z'
---

## Overview

Missing authorization in Microsoft Edge (Chromium-based) allows an unauthorized attacker to perform tampering locally.

## Affected

- `edge_chromium-based >= 1.0.0.0 < 151.0.4129.59`

## Remediation

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