CVE-2026-66313: CWE-346: Origin Validation Error in Microsoft Microsoft Edge (Chromium-based)
Origin validation error in Microsoft Edge (Chromium-based) allows an unauthorized attacker to perform tampering locally.
AI Analysis
Technical Summary
This vulnerability, identified as CVE-2026-66313 and classified under CWE-346 (Origin Validation Error), affects Microsoft Edge (Chromium-based). It allows an unauthorized attacker to perform tampering locally due to improper origin validation. The CVSS 3.1 base score is 6.8, reflecting medium severity with high confidentiality impact, low integrity impact, and no availability impact. The attack vector is local, requiring low attack complexity and no privileges or user interaction. Microsoft has released an official fix for this vulnerability.
Potential Impact
The vulnerability allows unauthorized local attackers to tamper with the browser environment or data, potentially leading to confidentiality breaches. Integrity impact is low, and availability is not affected. There are no known exploits in the wild at this time.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the patch provided by Microsoft as detailed in the vendor advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66313 to remediate this vulnerability.
CVE-2026-66313: CWE-346: Origin Validation Error in Microsoft Microsoft Edge (Chromium-based)
Description
Origin validation error in Microsoft Edge (Chromium-based) allows an unauthorized attacker to perform tampering locally.
CVSS v3.1
Score 6.8medium
Affected software
Microsoft
Microsoft Edge (Chromium-based)
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability, identified as CVE-2026-66313 and classified under CWE-346 (Origin Validation Error), affects Microsoft Edge (Chromium-based). It allows an unauthorized attacker to perform tampering locally due to improper origin validation. The CVSS 3.1 base score is 6.8, reflecting medium severity with high confidentiality impact, low integrity impact, and no availability impact. The attack vector is local, requiring low attack complexity and no privileges or user interaction. Microsoft has released an official fix for this vulnerability.
Potential Impact
The vulnerability allows unauthorized local attackers to tamper with the browser environment or data, potentially leading to confidentiality breaches. Integrity impact is low, and availability is not affected. There are no known exploits in the wild at this time.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the patch provided by Microsoft as detailed in the vendor advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66313 to remediate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-07-24T18:06:51.295Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66313","vendor":"Microsoft"}]
Threat ID: 6a7121fcbf32cb7a3462c05e
Added to database: 08/03/2026, 23:19:24 UTC
Last enriched: 08/11/2026, 14:58:39 UTC
Last updated: 09/18/2026, 01:04:25 UTC
Views: 34
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