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CVE Tracker

CVE-2019-17026

Mozilla Firefox And Thunderbird Type Confusion Vulnerability

IN CISA KEV

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

Vendor
Mozilla
Product
Firefox and Thunderbird
CVSS
No score recorded (no NVD record loaded for this entry)
Published
Not recorded
NVD modified
Not recorded

CISA KEV

Date added
2021-11-03
Due date
2022-05-03
Ransomware use
Unknown
Required action
Apply updates per vendor instructions.

EPSS

46.3% chance of exploitation in the next 30 days (percentile 98th)

FIRST EPSS, updated 17 Oct 2026. About EPSS

CVSS is severity, EPSS is likelihood, KEV means already exploited. EPSS is a statistical probability, not a certainty: a low score does not make a bug safe, and a high one does not prove it is being exploited.

Data last updated 18 Oct 2026. Sources: NVD API 2.0, CISA KEV catalog, FIRST EPSS. Links: NVD, CISA KEV. Metadata only. ThreatWire does not host exploit code.