IRSSI-SA-2019-01 Irssi Security Advisory 
Use after free when hidden lines were expired from the scroll buffer. (CWE-417, CWE-825)
CVE-2019-5882  was assigned to this issue.
May affect the stability of Irssi.
- Irssi 1.1.0 and later
Upgrade to Irssi 1.1.2. Irssi 1.1.2 is a maintenance release in the 1.1 series, without any new features.
After installing the updated packages, one can issue the /upgrade command to load the new binary. TLS connections will require /reconnect.
- If lines are never hidden (no usage of /window hidelevel), this bug will not trigger.