CVE-2026-84126CWE-120

CVE-2026-84126

Medium · published September 1, 2026

CVSS v3.1
4.3
EPSS
0%
Percentile
22.9
In the wild
Unconfirmed
What it is

Incorrect boundary conditions in the Layout: Grid component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.

The record
Technical detail
CVSS v3.1
4.3 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00312 · 22.9th percentile
Weakness
CWE-120 · Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Published
2026-09-01T17:20Z
Affected products (2)
ProductVersionsFixed in
mozilla/firefox< 155.0.0155.0.0
mozilla/thunderbird< 155.0155.0
References (3)
https://bugzilla.mozilla.org/show_bug.cgi?id=2063893 · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-82/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-86/ · [email protected]
EPSS history
Timeline
  • 03 SEP 03:32Z
    EPSS moved — → 0%
    epss
  • 01 SEP 12:18Z
    Incorrect boundary conditions in the Layout: Grid component
    cvelistv5