CVE-2026-109705
criticalSandbox escape, site isolation issue due to incorrect boundary conditions, use-after-free in the Networking component.
Sandbox escape, site isolation issue due to incorrect boundary conditions, use-after-free in the Networking component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, Thunderbird 153.5, and Firefox ESR 115.44.
CVSS
9.6
9.6 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H Severity source: NVD CVSS v3.1 (134c704f-9b21-4f2e-91b3-4a467353bcc0)
Timeline (UTC)
Published: 2026-10-13 13:17
Modified: 2026-10-27 14:16
NVD status: Deferred
Last synced 18 hours ago
Verified against the source API 2026-10-28 11:30 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2040905 security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2026-106/ security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2026-108/ security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2026-109/ security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2026-110/ security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2026-119/ security@mozilla.org
Data sources
NVD CVE API 2.0 — fetched 2026-10-28 11:30 UTC · record ↗