by Kastro
Paper/Archive/CVE-2026-8956

CVE-2026-8956

Mozilla Firefox — Integer overflow in the Networking: JAR component

EPSS 0.6%CVSS 9.8
critical.is priorityof 100
39
CVSS 9.8 (ADP)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 49.0.490 × 209.8No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

Integer overflow in the Networking: JAR component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

Affected

ProductAffectedFixed inSource
Firefoxsee advisory140.11CNA
Thunderbirdsee advisory140.11CNA

Scores by source

CISA ADP9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refbugzilla.mozilla.org/show_bug.cgi?id=2032427refmozilla.org/security/advisories/mfsa2026-46refmozilla.org/security/advisories/mfsa2026-48refmozilla.org/security/advisories/mfsa2026-50refmozilla.org/security/advisories/mfsa2026-51