by Kastro
Paper/Archive/CVE-2026-109708

CVE-2026-109708

Mozilla Firefox — Sandbox escape due to incorrect boundary conditions in the Networking component

EPSS 0.3%CVSS 9.6
critical.is priorityof 100
34
CVSS 9.6 (ADP)9.6 / 10 × 3028.8Not in CISA KEV+300.0EPSS percentile 26.8.268 × 205.4No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

Sandbox escape due to incorrect boundary conditions 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.

Affected

ProductAffectedFixed inSource
Firefoxsee advisory115.44CNA
Thunderbirdsee advisory153.5CNA

Scores by source

CISA ADP9.6CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total

References

refbugzilla.mozilla.org/show_bug.cgi?id=2059151refmozilla.org/security/advisories/mfsa2026-106refmozilla.org/security/advisories/mfsa2026-108refmozilla.org/security/advisories/mfsa2026-109refmozilla.org/security/advisories/mfsa2026-110refmozilla.org/security/advisories/mfsa2026-119