Description
Site isolation issue in the DOM: Navigation component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.
Published: 2026-09-01
Score: 9.8 Critical
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Thu, 03 Sep 2026 18:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-200
CWE-285
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Thu, 03 Sep 2026 16:45:00 +0000

Type Values Removed Values Added
First Time appeared Mozilla thunderbird
Weaknesses CWE-346
CPEs cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
Vendors & Products Mozilla thunderbird
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}


Wed, 02 Sep 2026 03:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-200
CWE-285

Tue, 01 Sep 2026 22:00:00 +0000

Type Values Removed Values Added
Description Site isolation issue in the DOM: Navigation component. This vulnerability was fixed in Firefox 155 and Firefox ESR 153.2. Site isolation issue in the DOM: Navigation component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.
References

Tue, 01 Sep 2026 15:15:00 +0000

Type Values Removed Values Added
First Time appeared Mozilla
Mozilla firefox
Vendors & Products Mozilla
Mozilla firefox

Tue, 01 Sep 2026 12:45:00 +0000

Type Values Removed Values Added
Description Site isolation issue in the DOM: Navigation component. This vulnerability was fixed in Firefox 155 and Firefox ESR 153.2.
Title Site isolation issue in the DOM: Navigation component
References

Subscriptions

Mozilla Firefox Thunderbird
cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published:

Updated: 2026-09-03T17:23:51.826Z

Reserved: 2026-09-01T07:25:56.481Z

Link: CVE-2026-84140

cve-icon Vulnrichment

Updated: 2026-09-03T17:00:41.394Z

cve-icon NVD

Status : Modified

Published: 2026-09-01T13:20:08.127

Modified: 2026-09-03T18:17:26.597

Link: CVE-2026-84140

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-03T20:15:06Z

Weaknesses