CVE-2026-74946

Information disclosure due to incorrect boundary conditions in the Graphics: CanvasWebGL component

Published Aug 18, 2026 CVSS 3.1 · 8.8 High EPSS < 1% KEV · Not listed
Description
Information disclosure due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4750-1 firefox-esr security update
Debian DLA Debian DLA DLA-4754-1 thunderbird security update
Debian DSA Debian DSA DSA-6451-1 firefox-esr security update
Debian DSA Debian DSA DSA-6461-1 thunderbird security update
History
Type Values Removed Values Added
Description Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. Information disclosure due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
Title Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component Information disclosure due to incorrect boundary conditions in the Graphics: CanvasWebGL component
Type Values Removed Values Added
CPEs cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
Type Values Removed Values Added
First Time appeared Mozilla thunderbird
CPEs cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
Vendors & Products Mozilla thunderbird
Type Values Removed Values Added
Weaknesses CWE-20
Type Values Removed Values Added
Description Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1. Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
References
Type Values Removed Values Added
Weaknesses CWE-119
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Weaknesses CWE-20
Type Values Removed Values Added
First Time appeared Mozilla
Mozilla firefox
Vendors & Products Mozilla
Mozilla firefox
Type Values Removed Values Added
Description Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1.
Title Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mozilla
Published
Updated
Oct 28, 2026, 4:35 PM
Reserved
Aug 17, 2026, 11:57 AM
Status
Modified
Published
Aug 18, 2026, 1:17 PM
Modified
Oct 28, 2026, 5:18 PM
Severity
Important
Public date
Aug 18, 2026, 12:23 PM