CVE-2026-121603 PUBLISHED

Solanum before commit 2ea1382 contains a buffer overflow vulnerability in ms_kill() that allows malicious linked servers to corrupt memory by sending an overlong kill reason. Attackers controlling a rogue or compromised peer server can send a reason exceeding KILLLEN that overflows a static 512-byte buffer, crashing the ircd or potentially achieving remote code execution.

• Tristan Madani (Talence Security) finder
• aaronmdjones remediation developer

• https://github.com/solanum-ircd/solanum/pull/550
• https://github.com/solanum-ircd/solanum/commit/2ea1382e4262b212a91034258c466f0f6754cd61
• https://github.com/solanum-ircd/solanum/blob/7bc7e34c04711247b932666e19ae900cba884540/modules/core/m_kill.c#L277
• https://github.com/solanum-ircd/solanum
• VulnCheck Advisory: Solanum before commit 2ea1382 Buffer Overflow via Server-to-Server KILL Handler

• Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') CWE