Privilege Escalation Vulnerability in Firefox Application Update Component
CVE-2026-8952

8.8HIGH

Key Information:

Vendor

Mozilla
Status
Firefox
Thunderbird
Vendor
CVE Published:
19 May 2026

What is CVE-2026-8952?

A privilege escalation vulnerability was identified in the Application Update component of Firefox, allowing attackers to gain higher access levels than intended. This issue has been addressed in Firefox version 151 and poses a risk primarily to users of earlier versions. It is recommended that all users update to the latest version to mitigate any potential security threats.

Affected Version(s)

Firefox 151

Thunderbird 151

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2021727
https://www.mozilla.org/security/advisories/mfsa2026-46/
https://www.mozilla.org/security/advisories/mfsa2026-50/

CVSS V3.1

Score:
8.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Tomoya Nakanishi
.