CVE-2026-16390

Analyzed Analyzed - Analysis Complete

Mitigation Bypass in Firefox Enterprise Policies

Publication date: 2026-07-21

Last updated on: 2026-07-24

Assigner: Mozilla Corporation

Description

Mitigation bypass in the Enterprise Policies component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-07-21

Last Modified

2026-07-24

Generated

2026-08-11

AI Q&A

2026-07-21

EPSS Evaluated

2026-08-09

NVD

CVE-2026-16390

EUVD

EUVD-2026-46227

Affected Vendors & Products

Vendor	Product	Version / Range
mozilla	firefox	to 153.0.0 (exc)
mozilla	firefox	to 140.13.0 (exc)
mozilla	thunderbird	to 140.13.0 (exc)
mozilla	thunderbird	From 141.0 (inc) to 153.0 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-693	The product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product.

Attack-Flow Graph

Executive Summary

This vulnerability is a mitigation bypass in the Enterprise Policies component of Firefox. It allows attackers to bypass security measures that were meant to protect the browser from certain threats. The issue was addressed in Firefox version 153 and Firefox ESR version 140.13.

Detection Guidance

Detection requires checking Firefox and Firefox ESR versions. Compare installed versions against Firefox 153 and Firefox ESR 140.13. If versions are older, the system is vulnerable.

Impact Analysis

If exploited, this vulnerability could allow attackers to bypass security policies in Firefox, potentially leading to unauthorized access or execution of malicious code. Users running vulnerable versions of Firefox may be at risk of data breaches or malware infections.

Compliance Impact

The provided CVE data does not specify how this vulnerability impacts compliance with standards like GDPR or HIPAA. The description only mentions a mitigation bypass in Firefox's Enterprise Policies component, fixed in Firefox 153 and Firefox ESR 140.13.

Mitigation Strategies

Update Firefox to version 153 or later and Firefox ESR to version 140.13 or later to address the mitigation bypass in the Enterprise Policies component.

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