CVE-2019-9799: Mozilla Firefox

High severity, CVSS 7.5. EPSS: 1.1% chance of exploitation in the next 30 days.

Insufficient bounds checking of data during inter-process communication might allow a compromised content process to be able to read memory from the parent process under certain conditions. This vulnerability affects Firefox < 66.

Affected products

• Mozilla Firefox: before 66.0 (fixed in 66.0)

Published 2019-04-26. Last modified 2026-06-17.