CVE-2026-0881Critical· 10.0▾ MidnightSandbox escape in the Messaging System component. This vulnerability was fixed in Firefox 147 and Thunderbird 147.
▾ Midnight zone — Critical, or high with PoC / in-the-wild
impact 55 · likelihood 0.1 · exploitation 0
Need a working PoC? Pro members can cast a request and our team develops one — it lands right here.
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
0.3%
0.3% → 0.4%
Sandbox escape in the Messaging System component. This vulnerability was fixed in Firefox 147 and Thunderbird 147.
firefox < 147.0thunderbird < 147.0Upgrade past the affected range:
firefox 147.0thunderbird 147.0Connected by shared product, vendor, weakness, or advisory.
CVE-2026-0877High· 8.1Mitigation bypass in the DOM: Security component
CVE-2026-0891High· 8.1Memory safety bugs present in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146
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-2026-0879Critical· 9.8Sandbox escape due to incorrect boundary conditions in the Graphics component
CVE-2026-0878High· 8.0Sandbox escape due to incorrect boundary conditions in the Graphics: CanvasWebGL component