Paper/Archive/CVE-2026-84134

CVE-2026-84134

Mozilla Firefox — Other issue in the Profile Backup component

EPSS 0.6%CVSS 9.8

critical.is priorityof 100

39

CVSS 9.8 (ADP)9.8 / 10 × 3029.4 Not in CISA KEV+300.0 EPSS percentile 47.2.472 × 209.4 No public exploit+100.0 SSVC exploitation: none+100.0

Description · from the CVE record

Other issue in the Profile Backup component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.

Affected

ProductAffectedFixed inSource

Firefoxsee advisory153.2CNA

Thunderbirdsee advisory153.2CNA

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=2044882 refmozilla.org/security/advisories/mfsa2026-82 refmozilla.org/security/advisories/mfsa2026-85 refmozilla.org/security/advisories/mfsa2026-86 refmozilla.org/security/advisories/mfsa2026-88