VulnerabilityAnalyzed
CVE-2026-84126
This vulnerability was fixed in Firefox 155 and Thunderbird 155.
MEDIUM 4.3EPSS 0.31%
Does this matter?
Lower severity and a low EPSS score (0.31%). Track it; it rarely justifies an emergency change on its own.
Description
Incorrect boundary conditions in the Layout: Grid component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.
- CVSS 3.1
- 4.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
- EPSS
- 0.31% probability · 24th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-120
- Affected
- mozilla/firefox · mozilla/thunderbird
- Source
- security@mozilla.org
EPSS 0.3% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2063893Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-82/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-86/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.