CVE-2026-16396
Received Received - Intake

Privilege Escalation in Firefox WebExtensions

Publication date: 2026-07-21

Last updated on: 2026-07-21

Assigner: Mozilla Corporation

Description
Privilege escalation in WebExtensions. This vulnerability was fixed in Firefox 153 and Firefox ESR 140.13.

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Meta Information

Published
2026-07-21
Last Modified
2026-07-21
Generated
2026-07-21
AI Q&A
2026-07-21
EPSS Evaluated
N/A
NVD
CVE-2026-16396
EUVD
EUVD-2026-46234

Affected Vendors & Products

Showing 4 associated CPEs
Vendor Product Version / Range
mozilla firefox to 153 (inc)
mozilla firefox_esr to 140.13 (inc)
mozilla firefox 153
mozilla firefox_esr 140.13

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This is a privilege escalation vulnerability in WebExtensions, which are browser extensions for Firefox. It allows an attacker with limited permissions to gain higher privileges within the browser, potentially executing unauthorized actions.

Impact Analysis

If exploited, this vulnerability could allow an attacker to perform actions on your behalf within the browser, such as accessing sensitive data, modifying browser settings, or installing malicious extensions without your consent.

Mitigation Strategies

Update Firefox to version 153 or later and Firefox ESR to version 140.13 or later to address the privilege escalation vulnerability in WebExtensions.

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