Paper/Archive/CVE-2026-109772

CVE-2026-109772

Mozilla Firefox — Same-origin policy bypass in the DevTools component

EPSS 0.2%CVSS 9.1

critical.is priorityof 100

29

CVSS 9.1 (ADP)9.1 / 10 × 3027.3 Not in CISA KEV+300.0 EPSS percentile 7.6.076 × 201.5 No public exploit+100.0 SSVC exploitation: none+100.0

Description · from the CVE record

Same-origin policy bypass in the DevTools component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.

Affected

ProductAffectedFixed inSource

Firefoxsee advisory158CNA

Thunderbirdsee advisory158CNA

Scores by source

CISA ADP9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refbugzilla.mozilla.org/show_bug.cgi?id=2066063 refmozilla.org/security/advisories/mfsa2026-106 refmozilla.org/security/advisories/mfsa2026-109