VULNERABILITY INTELLIGENCE

CVE-2019-9792

CVSS score9.8 CRITICAL
EPSS probability13.20%
CISA KEVNot currently listed
Published2019-04-26
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Description

The IonMonkey just-in-time (JIT) compiler can leak an internal JS_OPTIMIZED_OUT magic value to the running script during a bailout. This magic value can then be used by JavaScript to achieve memory corruption, which results in a potentially exploitable crash. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.

Weakness classification

  • CWE-787: Out-of-bounds Write

Primary references