CVE-2019-9809
CVSS v3
7.5
HIGH
EPSS Score
1.6 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
If the source for resources on a page is through an FTP connection, it is possible to trigger a series of modal alert messages for these resources through invalid credentials or locations. These messages cannot be immediately dismissed, allowing for a denial of service (DOS) attack. This vulnerability affects Firefox < 66.
Technical details
- Published
- 2019-04-26
Frequently asked questions
What is CVE-2019-9809?
If the source for resources on a page is through an FTP connection, it is possible to trigger a series of modal alert messages for these resources through invalid credentials or locations. These messages cannot be immediately dismissed, allowing for a denial of service (DOS) attack. This vulnerability affects Firefox < 66.
Is CVE-2019-9809 actively exploited?
Active exploitation of CVE-2019-9809 has not been confirmed. Its EPSS score was 1.6% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2019-9809?
CVE-2019-9809 has a CVSS v3 base score of 7.5 (HIGH severity).
Is CVE-2019-9809 affecting your environment?
Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.
No credit card required · 500 free checks/month · Free API key
Other 2019 vulnerabilities worth triaging
Ranked by exploit probability (EPSS).