CVE-2026-109759 Details
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.
A site isolation vulnerability has been identified in the Networking component, affecting Firefox, Firefox ESR, Thunderbird, and their respective versions. This vulnerability arises from a site isolation issue, which can potentially be exploited in browser or browser-like contexts.
This vulnerability has been fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Oct 13, 2026CISA-ADP
Assessed Oct 19, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://bugzilla.mozilla.org/show_bug.cgi?id=2070252 | [email protected] | Issue TrackingPermission RequiredVendor |
| https://www.mozilla.org/security/advisories/mfsa2026-106/ | [email protected] | AdvisoryBundleVendor |
| https://www.mozilla.org/security/advisories/mfsa2026-108/ | [email protected] | AdvisoryBundleVendor |
| https://www.mozilla.org/security/advisories/mfsa2026-109/ | [email protected] | AdvisoryBundleVendor |
| https://www.mozilla.org/security/advisories/mfsa2026-110/ | [email protected] | AdvisoryBundleVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-346 | Origin Validation Error | CISA-ADP |
Affected Products
| Product | Versions |
|---|---|
| Mozilla Firefox | All versions |
CPE
Remediation | |
| Mozilla Firefox ESR | All versions |
CPE
Remediation
| |
| Mozilla Thunderbird | All versions |
CPE
Remediation
| |
Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Oct 19, 2026 | CVE Modified | CISA-ADP |
| Oct 13, 2026 | CVE Modified | [email protected] |
| Oct 13, 2026 | New CVE Received | [email protected] |