Critical severity · published Sep 15, 2026
CVE-2026-92059
Incorrect boundary conditions in the DOM: Editor component
9.3
CVSS
0.1%
EPSS
No
On KEV
Description
Incorrect boundary conditions in the DOM: Editor component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 1% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
Firefox · Mozilla
before 153.3.0; 154.0.0 before 156.0.0 · source: NVD
TH
Thunderbird · Mozilla
before 153.3.0; 154.0 before 156.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-92059
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-92059
Permissions Required
https://bugzilla.mozilla.org/show_bug.cgi?id=2068442
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-90/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-93/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-94/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-96/
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