vulnerability
MFSA2019-07 Firefox: Security vulnerabilities fixed in Firefox 66 (CVE-2019-9791)
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 8 | (AV:N/AC:L/Au:N/C:P/I:P/A:P) | Mar 19, 2019 | Mar 20, 2019 | Mar 27, 2026 |
Severity
8
CVSS
(AV:N/AC:L/Au:N/C:P/I:P/A:P)
Published
Mar 19, 2019
Added
Mar 20, 2019
Modified
Mar 27, 2026
Description
The type inference system allows the compilation of functions that can cause type confusions between arbitrary objects when compiled through the IonMonkey just-in-time (JIT) compiler and when the constructor function is entered through on-stack replacement (OSR). This allows for possible arbitrary reading and writing of objects during an exploitable crash. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.
Solution
mozilla-firefox-upgrade-66_0
Rapid7 Labs
2026 Global Threat Landscape Report
The predictive window has collapsed. Exploitation follows disclosure in days. See how attackers are accelerating and how to stay ahead.