STIGQter: STIG Summary: Mozilla Firefox Security Technical Implementation Guide Version: 6 Release: 8 Benchmark Date: 01 Jul 2026:

Firefox private browsing must be disabled.

DISA Rule

SV-251563r960963_rule

Vulnerability Number

V-251563

Group Title

SRG-APP-000141

Rule Version

FFOX-00-000019

Severity

CAT II

CCI(s)

• CCI-000381 - Configure the system to provide only organization-defined mission essential capabilities.

Weight

10

Fix Recommendation

Windows group policy:
1. Open the group policy editor tool with "gpedit.msc".
2. Navigate to Policy Path: Computer Configuration\Administrative Templates\Mozilla\Firefox
Policy Name: Disable Private Browsing
Policy State: Enabled

macOS "plist" file:
Add the following:
<key>DisablePrivateBrowsing</key>
<true/>

Linux "policies.json" file:
Add the following in the policies section:
"DisablePrivateBrowsing": true

Check Contents

Type "about:policies" in the browser window.

If "DisablePrivateBrowsing" is not displayed under Policy Name or the Policy Value is not "true", this is a finding.

Vulnerability Number

V-251563

Documentable

False

Rule Version

FFOX-00-000019

Severity Override Guidance

Type "about:policies" in the browser window.

If "DisablePrivateBrowsing" is not displayed under Policy Name or the Policy Value is not "true", this is a finding.

Check Content Reference

M

Target Key

5446