CVE-2026-0879Critical· 9.8▾ MidnightSandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox 147, Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.
▾ Midnight zone — Critical, or high with PoC / in-the-wild
impact 53.9 · likelihood 0.1 · exploitation 0
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Exploit-prediction probability, daily snapshots since Jul 4.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
Last analysed / modified upstream
0.5%
0.5% → 0.6%
Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox 147, Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.
firefox < 115.32.0firefox < 147.0firefox >= 128.0, < 140.7.0thunderbird < 140.7.0thunderbird < 147.0Upgrade past the affected range:
firefox 140.7.0thunderbird 147.0Connected by shared product, vendor, weakness, or advisory.
CVE-2026-0891High· 8.1Memory safety bugs present in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146
CVE-2026-0878High· 8.0Sandbox escape due to incorrect boundary conditions in the Graphics: CanvasWebGL component
CVE-2026-0882High· 8.8Use-after-free in the IPC component
CVE-2026-0880High· 8.8Sandbox escape due to integer overflow in the Graphics component
CVE-2026-0877High· 8.1Mitigation bypass in the DOM: Security component
CVE-2026-0881Critical· 10.0Sandbox escape in the Messaging System component