CVE-2011-1947: Fetchmail

Medium severity, CVSS 5.0. EPSS: 2.6% chance of exploitation in the next 30 days.

fetchmail 5.9.9 through 6.3.19 does not properly limit the wait time after issuing a (1) STARTTLS or (2) STLS request, which allows remote servers to cause a denial of service (application hang) by acknowledging the request but not sending additional packets.

Affected products

• Fetchmail Fetchmail: version 5.9.9 only; version 5.9.10 only; version 5.9.11 only; version 5.9.13 only; version 6.0.0 only; version 6.1.0 only; …

Published 2011-06-02. Last modified 2026-06-16.