by Kastro
Paper/Archive/CVE-2026-100794

CVE-2026-100794

Mozilla Thunderbird — Sandbox escape due to incorrect boundary conditions in the Internationalization 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 25.1.251 × 205.0No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

Sandbox escape due to incorrect boundary conditions in the Internationalization component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, and Firefox ESR 140.17.

Affected

ProductAffectedFixed inSource
Thunderbirdsee advisory140.17CNA
Firefoxsee advisory140.17CNA

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=2028871refmozilla.org/security/advisories/mfsa2026-100refmozilla.org/security/advisories/mfsa2026-101refmozilla.org/security/advisories/mfsa2026-102refmozilla.org/security/advisories/mfsa2026-103refmozilla.org/security/advisories/mfsa2026-97refmozilla.org/security/advisories/mfsa2026-99