CVE-2026-0878

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2026-0878
Sandbox escape due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This vulnerability affects Firefox < 147, Firefox ESR < 140.7, Thunderbird < 147, and Thunderbird < 140.7.

8.0 /10

CVSS v3 : HIGH

V3 Legend

Vector :

Exploitability : 1.6 / Impact : 5.8

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope CHANGED

References
Link Resource
https://bugzilla.mozilla.org/show_bug.cgi?id=2003989 Permissions Required
https://www.mozilla.org/security/advisories/mfsa2026-01/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-03/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-04/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-05/ Vendor Advisory
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*
History

22 Jan 2026, 18:59

Type Values Removed Values Added
First Time Mozilla
Mozilla firefox
Mozilla thunderbird
CPE cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
References () https://bugzilla.mozilla.org/show_bug.cgi?id=2003989 - () https://bugzilla.mozilla.org/show_bug.cgi?id=2003989 - Permissions Required
References () https://www.mozilla.org/security/advisories/mfsa2026-01/ - () https://www.mozilla.org/security/advisories/mfsa2026-01/ - Vendor Advisory
References () https://www.mozilla.org/security/advisories/mfsa2026-03/ - () https://www.mozilla.org/security/advisories/mfsa2026-03/ - Vendor Advisory
References () https://www.mozilla.org/security/advisories/mfsa2026-04/ - () https://www.mozilla.org/security/advisories/mfsa2026-04/ - Vendor Advisory
References () https://www.mozilla.org/security/advisories/mfsa2026-05/ - () https://www.mozilla.org/security/advisories/mfsa2026-05/ - Vendor Advisory

15 Jan 2026, 10:16

Type Values Removed Values Added
Summary (en) Sandbox escape due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This vulnerability affects Firefox < 147 and Firefox ESR < 140.7. (en) Sandbox escape due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This vulnerability affects Firefox < 147, Firefox ESR < 140.7, Thunderbird < 147, and Thunderbird < 140.7.
References
  • () https://www.mozilla.org/security/advisories/mfsa2026-04/ -
  • () https://www.mozilla.org/security/advisories/mfsa2026-05/ -

13 Jan 2026, 16:16

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 8.0
CWE CWE-119
CWE-20

13 Jan 2026, 14:16

Type Values Removed Values Added
New CVE
Information

Published : 2026-01-13 14:16

Updated : 2026-01-22 18:59

NVD link : CVE-2026-0878

Mitre link : CVE-2026-0878

CVE.ORG link : CVE-2026-0878

JSON object : View

Products Affected

mozilla

  • thunderbird
  • firefox
CWE
CWE-20

Improper Input Validation

CWE-119

Improper Restriction of Operations within the Bounds of a Memory Buffer