Buffer overflow in Solanum-Ircd Solanum
CVE-2026-121603
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/solanum-ircd/solanum/pull/550 (issue-tracking, patch)
- github.com/solanum-ircd/solanum/commit/2ea1382e4262b212a91034258c466f0f6754cd61 (patch)
- github.com/solanum-ircd/solanum/blob/7bc7e34c04711247b932666e19ae900cba884540/m… (technical-description)
- github.com/solanum-ircd/solanum (product)
- www.vulncheck.com/advisories/solanum-before-commit-2ea1382-buffer-overflow-via-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-121603?
- CVE-2026-121603 is a medium-severity vulnerability in Solanum-Ircd Solanum, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 6.5/10. Published 2026-11-03.
- How severe is CVE-2026-121603?
- Medium severity. CVSS v3 base score is 6.5 out of 10.