Paper/Archive/CVE-2026-100787

CVE-2026-100787

Mozilla Firefox — Sandbox escape in the XUL component

EPSS 0.3%CVSS 9.6

critical.is priorityof 100

33

CVSS 9.6 (ADP)9.6 / 10 × 3028.8 Not in CISA KEV+300.0 EPSS percentile 22.7.227 × 204.5 No public exploit+100.0 SSVC exploitation: none+100.0

Description · from the CVE record

Sandbox escape in the XUL component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 153.4, and Firefox 157.

Affected

ProductAffectedFixed inSource

Firefoxsee advisory153.4CNA

Thunderbirdsee advisory153.4CNA

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=2071068 refmozilla.org/security/advisories/mfsa2026-100 refmozilla.org/security/advisories/mfsa2026-101 refmozilla.org/security/advisories/mfsa2026-103 refmozilla.org/security/advisories/mfsa2026-97