CVE-2026-109759: Vulnerability in Mozilla Firefox
Description
Site isolation issue in the Networking component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.
Affected software
Mozilla
Firefox
Mozilla
Thunderbird
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-109759 is a vulnerability related to site isolation within the networking component of Mozilla Firefox. The flaw could potentially impact the browser's security model by affecting site isolation mechanisms. Mozilla fixed this vulnerability in Firefox 158 and Firefox ESR 153.5.
Potential Impact
The vulnerability affects site isolation in Firefox's networking component, which could potentially allow security boundary bypasses between sites. However, no specific exploitation details or active exploits in the wild have been reported.
Mitigation Recommendations
Users should update to Firefox 158 or later, or Firefox ESR 153.5 or later, to ensure the vulnerability is patched. Since official fixes are available, applying these updates fully mitigates the issue.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-10-13T00:48:22.956Z
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-106/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-108/","vendor":"Mozilla"}]
Threat ID: 6ace2c4d2cdf04f65661d55a
Added to database: 10/13/2026, 13:04:13 UTC
Last enriched: 10/13/2026, 13:34:30 UTC
Last updated: 10/13/2026, 18:57:33 UTC
Views: 8
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