CVE-2019-17026
HIGHCISA KEVEPSS 99th pctlDescription
Incorrect alias information in IonMonkey JIT compiler for setting array elements could lead to a type confusion. We are aware of targeted attacks in the wild abusing this flaw. This vulnerability affects Firefox ESR < 68.4.1, Thunderbird < 68.4.1, and Firefox < 72.0.1.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Exploit Intelligence
Very high risk: more likely to be exploited than 99% of all known CVEs.
Mozilla Firefox And Thunderbird Type Confusion Vulnerability
Mozilla Firefox and Thunderbird contain a type confusion vulnerability due to incorrect alias information in the IonMonkey JIT compiler when setting array elements.
Apply updates per vendor instructions.
Remediation due: 2022-05-03
References
- http://packetstormsecurity.com/files/162568/Firefox-72-IonMonkey-JIT-Type-Confusion.html
- https://bugzilla.mozilla.org/show_bug.cgi?id=1607443
- https://security.gentoo.org/glsa/202003-02
- https://usn.ubuntu.com/4335-1/
- https://www.mozilla.org/security/advisories/mfsa2020-03/
- https://www.mozilla.org/security/advisories/mfsa2020-04/
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-17026
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Start freeThis product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-11-04.