CVEvulnerability

CVE-2019-17026

8.8 HIGH Known exploited Published 2020-03-02 Modified 2026-06-17 Official page ↗

CISA Known Exploited Vulnerability

Mozilla Firefox And Thunderbird Type Confusion Vulnerability — Mozilla Firefox and Thunderbird

Mozilla Firefox and Thunderbird contain a type confusion vulnerability due to incorrect alias information in the IonMonkey JIT compiler when setting array elements.

Added to KEV: 2021-11-03
Remediation due: 2022-05-03
Ransomware use: Unknown
Required action: Apply updates per vendor instructions.
Notes: https://nvd.nist.gov/vuln/detail/CVE-2019-17026

Status: Analyzed
Published: 2020-03-02
Last modified: 2026-06-17
Assigner: [email protected]
CVSS 3.1 ([email protected]): 8.8 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS 3.1 (134c704f-9b21-4f2e-91b3-4a467353bcc0): 8.8 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS 2.0 ([email protected]): 6.8 MEDIUM — AV:N/AC:M/Au:N/C:P/I:P/A:P
Weaknesses: CWE-843

Description

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.

Affected configurations

• mozilla firefox (< 68.4.1) • mozilla firefox (< 72.0.1) • mozilla thunderbird (< 68.4.1) • canonical ubuntu linux 16.04

Weakness · CWE (1)

CWE-843 Access of Resource Using Incompatible Type weakness

References