Spoofing Vulnerability in Popup Blocker in Firefox by Mozilla
CVE-2026-8964

7.5HIGH

Key Information:

Vendor

Mozilla
Status
Firefox
Thunderbird
Vendor
CVE Published:
19 May 2026

What is CVE-2026-8964?

A spoofing issue in the Popup Blocker component of Firefox allows attackers to manipulate user interactions, potentially leading to unauthorized content or actions. This vulnerability has been addressed in Firefox version 151, enhancing the security of the Popup Blocker feature.

Affected Version(s)

Firefox 151

Thunderbird 151

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2025170
https://www.mozilla.org/security/advisories/mfsa2026-46/
https://www.mozilla.org/security/advisories/mfsa2026-50/

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
High
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Satoki Tsuji
.