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CVE-2019-17026: Mozilla Firefox And Thunderbird Type Confusion Vulnerability

criticalknown exploitedpublic exploitCVE-2019-17026
Actively exploited. At least one CVE in this advisory is listed in the CISA Known Exploited Vulnerabilities catalog — exploitation has been observed in the wild. Treat remediation as urgent.
Mozilla Firefox and Thunderbird contain a type confusion vulnerability due to incorrect alias information in the IonMonkey JIT compiler when setting array elements.

CSIRTS triage

vendor: Mozillaproduct: Firefox, ThunderbirdOther
What
The vulnerability is a type confusion issue in the IonMonkey JIT compiler.
Who is affected
Users of Mozilla Firefox and Thunderbird are affected.
Urgency
Immediate action is necessary due to the critical nature of the vulnerability.
Action
Update to the latest versions of Firefox and Thunderbird.

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Details

Source
CISA Known Exploited Vulnerabilities (US · database · site)
Severity
critical
Published
2021-11-03
Exploitation
Observed in the wild (CISA KEV)

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2019-17026

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Referenced CVEs

CVECSIRTS overviewExternal
CVE-2019-17026coverage & exploitation statusNVD · CVE.org

Recent advisories for Mozilla Firefox And

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

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