CVE-2026-8964

Spoofing issue in the Popup Blocker component

Published May 19, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
Spoofing issue in the Popup Blocker component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Mozilla thunderbird
CPEs cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*
Vendors & Products Mozilla thunderbird
Type Values Removed Values Added
Weaknesses CWE-1021
CWE-200
Type Values Removed Values Added
Description Spoofing issue in the Popup Blocker component. This vulnerability was fixed in Firefox 151. Spoofing issue in the Popup Blocker component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.
References
Type Values Removed Values Added
First Time appeared Mozilla
Mozilla firefox
Vendors & Products Mozilla
Mozilla firefox
Type Values Removed Values Added
Weaknesses CWE-1021
CWE-200
Type Values Removed Values Added
Weaknesses CWE-451
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'}

ssvc

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

Type Values Removed Values Added
Description Spoofing issue in the Popup Blocker component. This vulnerability was fixed in Firefox 151.
Title Spoofing issue in the Popup Blocker component
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mozilla
Published
Updated
May 19, 2026, 5:10 PM
Reserved
May 19, 2026, 12:30 PM
Status
Analyzed
Published
May 19, 2026, 2:16 PM
Modified
Jul 23, 2026, 8:10 PM