CVE-2026-84126: Incorrect boundary conditions in the Layout: Grid component
Published Sep 1, 2026
·Updated
Incorrect boundary conditions in the Layout: Grid component. This vulnerability was fixed in Firefox 155.
Affected Software
1 affected componentFixes available
Mozilla Firefox<155
155
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 155 - Upgrade
Upgrade
Firefoxto a version that resolves this vulnerability.Fixed in 155
Event History
Sep 1, 2026
CVE Published
via Mozilla·12:00 AM
Data Sourced
via Mozilla·12:00 AM
DescriptionSeverityAffected Software
CVE Published
via MITRE·12:18 PM
Data Sourced
via MITRE·12:18 PM
Description
Peer vulnerabilities
Found alongside the following vulnerabilities.
- CVE-2026-84117
- CVE-2026-84118
- CVE-2026-84119
- CVE-2026-84120
- CVE-2026-84121
- CVE-2026-84122
- CVE-2026-84123
- CVE-2026-84124
- CVE-2026-84125
- CVE-2026-84126
- CVE-2026-84127
- CVE-2026-84128
- CVE-2026-84129
- CVE-2026-84130
- CVE-2026-84131
- CVE-2026-84132
- CVE-2026-84133
- CVE-2026-84134
- CVE-2026-84135
- CVE-2026-84136
- CVE-2026-84137
- CVE-2026-84138
- CVE-2026-84139
- CVE-2026-84140
- CVE-2026-84141
- CVE-2026-84142
- CVE-2026-84143
- CVE-2026-84144
- CVE-2026-84145
Frequently Asked Questions
1
Which Firefox versions need to be updated?
The issue was fixed in Firefox 155. The provided information does not identify the first affected version or whether any specific release channels are excluded.
2
What exploitation conditions or temporary mitigations are documented?
The provided information does not describe attacker prerequisites, affected default settings, indicators of compromise, or a workaround for systems that cannot yet update. Updating to Firefox 155 is the documented remediation.