CVE-2026-92034: Site isolation issue in the Graphics component

Critical severity · published Sep 15, 2026

CVE-2026-92034

Site isolation issue in the Graphics component

9.1

CVSS

0.3%

EPSS

On KEV

Description

Site isolation issue in the Graphics component. This vulnerability was fixed in Firefox 156 and Thunderbird 156.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

Attack vector

Network

Complexity

Low

Privileges

None

User interaction

None

Confidentiality

None

Integrity

High

Availability

High

Scope

Unchanged

Exploitation

Is it being used?

Exploit prediction (EPSS)0.3% · higher than 20% of CVEs

Exploited in the wildNo evidence yet

CISA KEVNot listed

Ransomware campaign useNot known

Affected products

Which versions

Firefox · Mozilla

before 156.0.0 · source: NVD

Thunderbird · Mozilla

before 156.0 · source: NVD

Affected product

Firefox

Mozilla

All Firefox CVEs

References

NVD

https://nvd.nist.gov/vuln/detail/CVE-2026-92034

CVE.org

https://www.cve.org/CVERecord?id=CVE-2026-92034

Permissions Required

https://bugzilla.mozilla.org/show_bug.cgi?id=2060295

Vendor Advisory

https://www.mozilla.org/security/advisories/mfsa2026-90/

Vendor Advisory

https://www.mozilla.org/security/advisories/mfsa2026-94/