CVE-2026-0878

HIGH

Firefox < 147.0 and 140.7-140.* - Sandbox Escape via CanvasWebGL Boundary Condition Mismanagement

Title source: llm
STIX 2.1

Description

Sandbox escape due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.

References (5)

Core 5

Scores

CVSS v3 8.0
EPSS 0.0003
EPSS Percentile 10.1%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-119 CWE-20
Status published
Products (8)
mozilla/firefox < 140.7.0
mozilla/firefox < 147.0
Mozilla/Firefox 140.7 - 140.*
Mozilla/Firefox 147
mozilla/thunderbird < 140.7.0
mozilla/thunderbird < 147.0
Mozilla/Thunderbird 140.7 - 140.*
Mozilla/Thunderbird 147
Published Jan 13, 2026
Tracked Since Feb 18, 2026