Medium (5.3). EPSS 2.5% chance of exploitation in the next 30 days.
Certain response codes in FTP connections can result in the use of uninitialized values for ports in FTP operations. This vulnerability affects Firefox < 52, Firefox ESR < 45.8, Thunderbird < 52, and Thunderbird < 45.8.
Severity
CVSS 3.0
5.3 medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS
2.5% chance of exploitation in the next 30 days; higher than 85% of CVEs (scores of 2026-10-31)