irssi vulnerabilities (OSS-Fuzz)

4 vulnerabilities.

• irssi OSS-Fuzz Heap-use-after-free in module_check_cast OSV-2021-664 Fix available No scoreApril 21, 2021
• irssi OSS-Fuzz Heap-buffer-overflow in unescape_tag OSV-2021-457 Fix available No scoreMarch 1, 2021
• irssi OSS-Fuzz Heap-buffer-overflow in irc_parse_message_tags OSV-2021-454 Fix available No scoreFebruary 28, 2021
• irssi OSS-Fuzz Bad-free in sig_destroyed OSV-2020-299 Fix available No scoreJune 30, 2020