CVE-2026-84126 json
Incorrect boundary conditions in the Layout: Grid component
published 2026-09-01 2 mo ago modified 2026-09-03 2 mo ago also EUVD-2026-69075
- cvss
- 4.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 24%
- public exploits
- 0
- none known
Summary
Incorrect boundary conditions in the Layout: Grid component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.
Patch / fix
- mozilla firefox 155.0.0
- mozilla thunderbird 155.0
- MozillaFirefox openSUSE Tumbleweed 155.0-1.1
opensuse advisories openSUSE-SU-2026:11677-1
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-84126 updated cvss 7.5
firefox: thunderbird: Incorrect boundary conditions in the Layout: Grid component
-
Red Hat Enterprise Linux 6 firefox, thunderbird Red Hat Enterprise Linux 7 firefox, thunderbird Red Hat Enterprise Linux 8 firefox, thunderbird Red Hat Enterprise Linux 9 firefox, firefox-x11, thunderbird Red Hat Enterprise Linux 10 firefox, thunderbird, rhel10/firefox-flatpak, rhel10/thunderbird-flatpaknot affected: vulnerable code not present
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 2 mo ago
Exploit prediction
0.31% chance of exploitation in the next 30 days, higher than 24% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 4.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N |
| CNA | 3.1 | 4.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N |
Affected products
- Mozilla Firefox
- Mozilla Thunderbird
Classification
- Weakness
-
- CWE-120 Buffer Copy without Checking Size of Input
References
-
mozilla.org
/security/advisories/mfsa2026-82/
vendor-advisory
-
mozilla.org
/security/advisories/mfsa2026-86/
vendor-advisory
-
bugzilla.mozilla.org
/show_bug.cgi?id=2063893
permissions-required
Sources
- CVE List CVE-2026-84126
- NVD CVE-2026-84126
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