CVE-2026-84126
published 2026-09-01CVE-2026-84126: Incorrect boundary conditions in the Layout: Grid component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.
PriorityP418medium4.3CVSS 3.1
AVNACLPRNUIRSUCLINAN
EPSS
0.31%
22.8th percentile
Incorrect boundary conditions in the Layout: Grid component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.
Affected
4 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 155 | Firefox 155 |
| mozilla | firefox | < 155.0.0 | 155.0.0 |
| mozilla | thunderbird | < Thunderbird 155 | Thunderbird 155 |
| mozilla | thunderbird | < 155.0 | 155.0 |
CVSS provenance
nvdv3.14.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
vendor_redhat4.3MEDIUM
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VulDB
Mozilla Firefox up to 154 Layout Grid integer overflow
vuldb·2026-09-07·CVSS 4.3
CVE-2026-84126 [MEDIUM] Mozilla Firefox up to 154 Layout Grid integer overflow
A vulnerability was found in Mozilla Firefox up to 154. It has been classified as critical. Affected is an unknown function of the component Layout Grid. Performing a manipulation results in integer overflow.
This vulnerability is known as CVE-2026-84126. Remote exploitation of the attack is possible. No exploit is available.
Upgrading the affected component is recommended.
GHSA
Incorrect boundary conditions in the Layout: Grid component.
ghsa_unreviewed·2026-09-01
CVE-2026-84126 [MEDIUM] CWE-120 Incorrect boundary conditions in the Layout: Grid component.
Incorrect boundary conditions in the Layout: Grid component. This vulnerability was fixed in Firefox 155.
Red Hat
firefox: thunderbird: Incorrect boundary conditions in the Layout: Grid component
vendor_redhat·2026-09-01·CVSS 4.3
CVE-2026-84126 [MEDIUM] CWE-787 firefox: thunderbird: Incorrect boundary conditions in the Layout: Grid component
firefox: thunderbird: Incorrect boundary conditions in the Layout: Grid component
Incorrect boundary conditions in the Layout: Grid component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Incorrect boundary conditions in the Layout: Grid component
Statement: Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
Package: firefox (Red Hat Enterprise Linux 10) - Not affected
Package: rhel10/firefox-flatpak (Red Hat Enterprise Linux 10) - Not affected
Package: rhel10/thunderbird-flatpak (Red Hat Enterprise Linux 10) - Not affected
Package: thunderbird (Red Hat Enterprise Linux 10) - Not af
Mozilla
Mozilla Foundation Security Advisory 2026-86: CVE-2026-84126
vendor_mozilla·CVSS 4.3
CVE-2026-84126 [MEDIUM] Mozilla Foundation Security Advisory 2026-86: CVE-2026-84126
Mozilla Foundation Security Advisory 2026-86
CVE: CVE-2026-84126
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 155
Mozilla
Mozilla Foundation Security Advisory 2026-82: CVE-2026-84126
vendor_mozilla·CVSS 4.3
CVE-2026-84126 [MEDIUM] Mozilla Foundation Security Advisory 2026-82: CVE-2026-84126
Mozilla Foundation Security Advisory 2026-82
CVE: CVE-2026-84126
Product: Firefox
Impact: high
Fixed in: Firefox 155
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-84126 firefox: thunderbird: Incorrect boundary conditions in the Layout: Grid component
bugzilla·2026-09-01·CVSS 4.3
CVE-2026-84126 [MEDIUM] CVE-2026-84126 firefox: thunderbird: Incorrect boundary conditions in the Layout: Grid component
CVE-2026-84126 firefox: thunderbird: Incorrect boundary conditions in the Layout: Grid component
Incorrect boundary conditions in the Layout: Grid component. This vulnerability was fixed in Firefox 155.
Hackernews
⚡ Weekly Recap: Chrome 0-Day, Router Hijacks, Coder Supply Chain Attack and More
blogs_hackernews·2026-09-07·CVSS 6.9
CVE-2026-86206 [MEDIUM] ⚡ Weekly Recap: Chrome 0-Day, Router Hijacks, Coder Supply Chain Attack and More
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Published