"Pegasus Mail is prone to a remote buffer-overflow vulnerability because
it fails to properly sanitize user-supplied input.
An attacker may exploit this issue to execute arbitrary code in the
context of the vulnerable application. Failed exploit attempts will
likely result in a denial-of-service condition.
Pegasus Mail 4.51 is vulnerable; other versions may also be affected."
The vendor has not released a patch to deal with this issue as of yet.
If you have Pegasus Mail users, please watch for updates. Consider
using webmail until a fix has been released.