by Kastro
Paper/Archive/CVE-2026-117997

CVE-2026-117997

Mozilla Firefox — Sandbox escape due to use-after-free in the Widget component

EPSS 0.2%CVSS 9.6
critical.is priorityof 100
30
CVSS 9.6 (ADP)9.6 / 10 × 3028.8Not in CISA KEV+300.0EPSS percentile 7.8.078 × 201.6No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

Sandbox escape due to use-after-free in the Widget component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.

Affected

ProductAffectedFixed inSource
Firefoxsee advisory153.6CNA
Thunderbirdsee advisory153.6CNA

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=2081560refmozilla.org/security/advisories/mfsa2026-118refmozilla.org/security/advisories/mfsa2026-120refmozilla.org/security/advisories/mfsa2026-121refmozilla.org/security/advisories/mfsa2026-122