November 3, 2021 · Applied Cybernetics Group
CVE-2019-17026 — Mozilla Firefox and Thunderbird
Mozilla Firefox And Thunderbird Type Confusion Vulnerability
- Added to KEV
2021-11-03- Federal due date
2022-05-03- Vendor
- Mozilla
- Product
- Firefox and Thunderbird
- EPSS
- 98.1th percentile (score 0.562, as of
2026-06-08) - NVD CVSS v3.1
- —
- Ransomware use
- Unknown
- Upstream
- https://nvd.nist.gov/vuln/detail/CVE-2019-17026
CISA short description
Mozilla Firefox and Thunderbird contain a type confusion vulnerability due to incorrect alias information in the IonMonkey JIT compiler when setting array elements.
Required action
Apply updates per vendor instructions.