CVE-2026-121602: Solanum before commit 2ce64de Heap Buffer Overflow via JOIN and SJOIN

Solanum before commit 2ce64de contains a heap-based buffer overflow vulnerability that allows a malicious linked server to corrupt memory by sending overlong channel names in JOIN or SJOIN messages. Attackers controlling a peer server can trigger strcpy and sprintf overflows in msjoin and mssjoin to crash the ircd or potentially achieve remote code execution.