Mozilla Firefox and Thunderbird Denial-of-Service Vulnerability
CISA lists this Mozilla Firefox and Thunderbird vulnerability as known exploited. The vendor's advisory has the fixed versions.
CISA catalog record
Mozilla Firefox and Thunderbird do not properly handle onreadystatechange events in conjunction with page reloading, which allows remote attackers to cause a denial-of-service (DoS) or possibly execute malicious code via a crafted web site.
- Product
- Firefox and Thunderbird
- Added to KEV
- 28 Mar 2022
- Federal remediation due
- 18 Apr 2022
- Known ransomware use
- Not reported
What changed
First observed 14 Oct 2026No field changes in the recorded history.
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