CVE-2026-100809: Vulnerability in Mozilla Firefox
Same-origin policy bypass in the DevTools component. This vulnerability was fixed in Firefox ESR 153.4 and Firefox 157.
AI Analysis
Technical Summary
This vulnerability involves a bypass of the same-origin policy within the DevTools component of Mozilla Firefox. The same-origin policy is a critical security mechanism that restricts how documents or scripts loaded from one origin can interact with resources from another origin. The flaw was fixed by Mozilla in Firefox ESR 153.4 and Firefox 157, as documented in the Mozilla Foundation Security Advisory 2026-100. There is no indication of active exploitation in the wild.
Potential Impact
The vulnerability could allow an attacker to bypass the same-origin policy within the Firefox DevTools component, potentially enabling unauthorized access to web content from different origins. This could lead to information disclosure or unauthorized interactions within the browser context. However, no active exploitation has been reported.
Mitigation Recommendations
A fix for this vulnerability is available and has been implemented in Firefox ESR 153.4 and Firefox 157. Users and administrators should update affected Firefox installations to these versions or later to remediate the issue. No additional mitigation steps are indicated by the vendor advisory.
CVE-2026-100809: Vulnerability in Mozilla Firefox
Description
Same-origin policy bypass in the DevTools component. This vulnerability was fixed in Firefox ESR 153.4 and Firefox 157.
Affected software
Mozilla
Firefox
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability involves a bypass of the same-origin policy within the DevTools component of Mozilla Firefox. The same-origin policy is a critical security mechanism that restricts how documents or scripts loaded from one origin can interact with resources from another origin. The flaw was fixed by Mozilla in Firefox ESR 153.4 and Firefox 157, as documented in the Mozilla Foundation Security Advisory 2026-100. There is no indication of active exploitation in the wild.
Potential Impact
The vulnerability could allow an attacker to bypass the same-origin policy within the Firefox DevTools component, potentially enabling unauthorized access to web content from different origins. This could lead to information disclosure or unauthorized interactions within the browser context. However, no active exploitation has been reported.
Mitigation Recommendations
A fix for this vulnerability is available and has been implemented in Firefox ESR 153.4 and Firefox 157. Users and administrators should update affected Firefox installations to these versions or later to remediate the issue. No additional mitigation steps are indicated by the vendor advisory.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-09-26T19:18:06.677Z
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-100/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-97/","vendor":"Mozilla"}]
Threat ID: 6abbb3f5f7a7c541066409b0
Added to database: 09/29/2026, 12:49:57 UTC
Last enriched: 09/29/2026, 13:04:02 UTC
Last updated: 09/29/2026, 18:20:13 UTC
Views: 6
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