High severity · published Sep 1, 2026
CVE-2026-84131
Privilege escalation due to invalid pointer in the Graphics component
8.8
CVSS
0.3%
EPSS
No
On KEV
Description
Privilege escalation due to invalid pointer in the Graphics component. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 26% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
Firefox · Mozilla
before 115.40.0; 116.0 before 140.15.0; 141.0.0 before 153.2.0; 154.0.0 before 155.0.0 · source: NVD
TH
Thunderbird · Mozilla
before 140.15.0; 141.0 before 153.2.0; 154.0 before 155.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-84131
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-84131
Permissions Required
https://bugzilla.mozilla.org/show_bug.cgi?id=2060008
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-82/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-83/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-84/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-85/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-86/
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