---
id: "CVE-2026-121602"
kind: "vulnerability"
aliases: ["CVE-2026-121602"]
title: "Solanum IRC server: linked-server overlong channel names overflow heap memory"
severity: "high"
cvss: 8.5
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["irc", "package", "self-hosted", "solanum"]
not_affected_if: ["no-server-links", "not-solanum"]
published_at: "2026-11-03T17:18:11+00:00"
first_seen_at: "2026-11-03T17:21:56+00:00"
updated_at: "2026-11-03T17:23:59+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121602", "first_seen_at": "2026-11-03T17:21:56+00:00"}]
---

# Solanum IRC server: linked-server overlong channel names overflow heap memory

Solanum, an IRC server daemon, copies channel names from JOIN and SJOIN messages into fixed-size buffers without a length check. A malicious server linked to it can send overlong names to crash the daemon or potentially run code on it.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check whether the server runs Solanum and what commit it was built from; the sources say the fix is commit `2ce64de` or later.
- Check whether the server accepts server-to-server links from peers you do not fully control.

## Fix

- Solanum: move to commit `2ce64de` or later (sources give no release version).

## Timeline

- 2026-11-03T17:21:56+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-121602

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/solanum-before-commit-2ce64de-heap-buffer-overflow-via-join-and-sjoin
- [fix] Patch: github.com https://github.com/solanum-ircd/solanum/commit/2ce64debf65e9710e9eea099ada93dbf6655b5ff

## From the sources

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 ms_join and ms_sjoin to crash the ircd or potentially achieve remote code execution.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_