CVE-2019-9791

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.

• CWE-843

• https://access.redhat.com/errata/RHSA-2019:0966Third Party Advisory
• https://access.redhat.com/errata/RHSA-2019:1144Third Party Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=1530958Exploit, Issue Tracking, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2019-07/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2019-08/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2019-11/Vendor Advisory
• https://access.redhat.com/errata/RHSA-2019:0966Third Party Advisory
• https://access.redhat.com/errata/RHSA-2019:1144Third Party Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=1530958Exploit, Issue Tracking, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2019-07/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2019-08/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2019-11/Vendor Advisory

Published

Apr 26, 2019

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2019-9779An issue was discovered in GNU LibreDWG 0.7 and 0.7.1645. Th…7.5
• CVE-2019-9785gitnote 3.1.0 allows remote attackers to execute arbitrary c…
• CVE-2019-9787WordPress before 5.1.1 does not properly filter comment cont…
• CVE-2019-9788Mozilla developers and community members reported memory saf…9.8
• CVE-2019-9789Mozilla developers and community members reported memory saf…
• CVE-2019-9790A use-after-free vulnerability can occur when a raw pointer …
• CVE-2019-9792The IonMonkey just-in-time (JIT) compiler can leak an intern…9.8
• CVE-2019-9793A mechanism was discovered that removes some bounds checking…
• CVE-2019-9794A vulnerability was discovered where specific command line a…
• CVE-2019-9795A vulnerability where type-confusion in the IonMonkey just-i…
• CVE-2019-9796A use-after-free vulnerability can occur when the SMIL anima…
• CVE-2019-9797Cross-origin images can be read in violation of the same-ori…