Privilege Escalation in Firefox Address Bar Component
CVE-2026-100820

8.8HIGH

Key Information:

Vendor

Mozilla

Vendor
CVE Published:
29 September 2026

What is CVE-2026-100820?

A privilege escalation issue exists in the Address Bar component of Firefox, which could allow attackers to gain higher permissions than intended. This vulnerability has been addressed in multiple versions, including Firefox ESR 153.4 and Firefox 157. Users are encouraged to update their browsers to the latest versions to ensure their security and protect against potential exploits.

Affected Version(s)

Firefox 140.17

Firefox 153.4

Firefox 157

References

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

Tran Quac
.