by Kastro
Paper/Archive/CVE-2026-100804

CVE-2026-100804

Mozilla Thunderbird — Sandbox escape due to use-after-free in the Preferences: Backend component

EPSS 0.3%CVSS 9.6
critical.is priorityof 100
33
CVSS 9.6 (ADP)9.6 / 10 × 3028.8Not in CISA KEV+300.0EPSS percentile 20.8.208 × 204.2No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

Sandbox escape due to use-after-free in the Preferences: Backend component. This vulnerability was fixed in Thunderbird 157 and Firefox 157.

Affected

ProductAffectedFixed inSource
Thunderbirdsee advisory157CNA
Firefoxsee advisory157CNA

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=2058647refmozilla.org/security/advisories/mfsa2026-101refmozilla.org/security/advisories/mfsa2026-97