Paper/Archive/CVE-2026-109750

CVE-2026-109750

Mozilla Firefox — Site isolation issue in the DOM: Web Authentication component

EPSS 0.4%CVSS 9.6

critical.is priorityof 100

35

CVSS 9.6 (ADP)9.6 / 10 × 3028.8 Not in CISA KEV+300.0 EPSS percentile 31.9.319 × 206.4 No public exploit+100.0 SSVC exploitation: none+100.0

Description · from the CVE record

Site isolation issue in the DOM: Web Authentication component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.

Affected

ProductAffectedFixed inSource

Firefoxsee advisory158CNA

Thunderbirdsee advisory158CNA

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=2067571 refmozilla.org/security/advisories/mfsa2026-106 refmozilla.org/security/advisories/mfsa2026-109