CVE-2019-9809

7.5 highEPSS 1.6%

High (7.5) in mozilla firefox. EPSS 1.6% chance of exploitation in the next 30 days.

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.

Severity

CVSS 3.0

7.5 high

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS: 1.6% chance of exploitation in the next 30 days; higher than 76% of CVEs (scores of 2026-10-31)
CWE: CWE-399
Published: 2019-04-26
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

mozilla:firefox

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1282430
https://bugzilla.mozilla.org/show_bug.cgi?id=1523249
https://www.mozilla.org/security/advisories/mfsa2019-07/
https://bugzilla.mozilla.org/show_bug.cgi?id=1282430
https://bugzilla.mozilla.org/show_bug.cgi?id=1523249

Check your stack JSON