Improper privilege management in Mozilla products - CVE-2026-100820
Published: September 29, 2026
Vulnerability identifier: #VU152843
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-100820
CWE-ID: CWE-269
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to escalate privileges.
The vulnerability exists due to improper privilege management in the Address Bar component when processing content. A remote attacker can trigger the component issue to escalate privileges.
Affected software
Firefox ESR
Mozilla Firefox
Firefox for Android
Mozilla Firefox
Firefox for Android
How to mitigate CVE-2026-100820
Install security update from vendor's website.
Firefox ESR - addressed in versions 140.17.0, 153.4.0
Firefox for Android - update to 157.0
Mozilla Firefox - update to 157.0
Firefox for Android - update to 157.0
Mozilla Firefox - update to 157.0