Is CVE-2019-17026 actively exploited?

Yes. CVE-2019-17026 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, which means exploitation in the wild has been confirmed.

Can CVE-2019-17026 be exploited remotely?

The attack vector of CVE-2019-17026 has not been classified yet.

What is the CVSS score of CVE-2019-17026?

CVE-2019-17026 has not received a CVSS score yet.

HOME VULNERABILITIESCVE-2019-17026

HIGHCISA KEVIN THE WILD

CVE-2019-17026

Published: November 3, 2021

EPSS:64.81%probability of exploitation in 30 daysPercentile:98.4th

Official Description

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

NVD Source

CISA KEV Advisory

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.

Added to KEV: 2021-11-03Federal patch deadline: 2022-05-03

Required Action (CISA)

Apply updates per vendor instructions.

Risk Analysis

Mozilla Firefox and Thunderbird are affected by a type confusion vulnerability in the IonMonkey JIT compiler. This flaw, caused by incorrect alias information when setting array elements, could lead to arbitrary code execution. With a high EPSS score of 0.64805 and confirmed in-the-wild exploitation, this is a critical browser and email client vulnerability.

This vulnerability is actively exploited in the wild and is included in CISA's KEV catalog, confirming its use by threat actors. Browser vulnerabilities are typically remotely exploitable.

Recommended Action

Users should update Mozilla Firefox and Thunderbird to the latest versions immediately. Ensure automatic updates are enabled for these applications.

Generated by the CTIWATCH analysis pipeline from this CVE's metadata (CVSS, EPSS, KEV status, exploit intelligence). Verify against vendor advisories before acting.

Technical Analysis

CVE-2019-17026 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

CISA has added CVE-2019-17026 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.