Cyber Resilience

CVE-2026-8964

High

Published: 19 May 2026

Published
19 May 2026
Modified
20 May 2026
KEV Added
—
Patch
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CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS Score 0.0030 21.7th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-8964 is a high-severity User Interface (UI) Misrepresentation of Critical Information (CWE-451) vulnerability in Mozilla Firefox. Its CVSS base score is 7.5 (High).

Operationally, ranked at the 21.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Spoofing issue in the Popup Blocker component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.

CWE(s)
CWE-451

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

Insufficient information to map techniques.
Confidence: LOW · MITRE ATT&CK Enterprise v18.1

CVEs Like This One

CVE-2025-8043Same product: Mozilla Firefox
CVE-2025-1020Same product: Mozilla Firefox
CVE-2026-4692Same product: Mozilla Firefox
CVE-2026-6746Same product: Mozilla Firefox
CVE-2026-6748Same product: Mozilla Firefox
CVE-2026-8965Same product: Mozilla Firefox
CVE-2026-6771Same product: Mozilla Firefox
CVE-2026-8956Same product: Mozilla Firefox
CVE-2026-8950Same product: Mozilla Firefox
CVE-2026-6761Same product: Mozilla Firefox

Affected Assets

mozilla
firefox
≤ 151.0.0
mozilla
thunderbird
≤ 151.0.0

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References