---
id: "CVE-2026-112007"
kind: "vulnerability"
aliases: ["CVE-2026-112007"]
title: "Schism Tracker: crafted ULT module overwrites heap, crashes the application"
severity: "medium"
cvss: 6.9
epss: null
exploited: false
status: "open"
category: "other"
products: []
ecosystems: []
tags: ["desktop", "music-software", "other", "schism-tracker"]
not_affected_if: ["no-untrusted-ult-files"]
published_at: "2026-10-18T12:17:13+00:00"
first_seen_at: "2026-10-23T21:57:15+00:00"
updated_at: "2026-10-25T03:41:02+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-112007", "first_seen_at": "2026-10-23T21:57:15+00:00"}]
---

# Schism Tracker: crafted ULT module overwrites heap, crashes the application

Schism Tracker, a music tracker app, fails to bounds-check the sample count when loading .ult module files. A crafted .ult file overwrites the instruments pointer array, so the app frees attacker-chosen pointers and crashes.

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

## How to check

- Run `schismtracker -v` or check the installed version against the date `20260524`, since the sources say versions through 20260524 are affected
- unknown whether the sources give a version-specific check beyond that

## Fix

- unknown: the sources do not name a fixed version or patch; check the Schism Tracker project for a release newer than `20260524`

## Timeline

- 2026-10-23T21:57:15+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-112007

## From the sources

Schism Tracker through 20260524 contains a heap out-of-bounds write vulnerability in fmt_ult_load_song() in fmt/ult.c that fails to clamp the one-byte sample count to MAX_SAMPLES. Attackers can supply a crafted .ult module that overwrites the instruments pointer array, causing csf_destroy() to free attacker-chosen pointers and crash the application.

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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_