Heap-based Buffer Overflow Affecting fluidsynth package, versions <2.3.4-1ubuntu0.1~esm1


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.59% (47th percentile)

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  • Snyk IDSNYK-UBUNTU2404-FLUIDSYNTH-18323391
  • published1 Oct 2026
  • disclosed18 Sept 2026

Introduced: 18 Sep 2026

NewCVE-2026-58264  (opens in a new tab)
CWE-122  (opens in a new tab)

How to fix?

Upgrade Ubuntu:24.04 fluidsynth to version 2.3.4-1ubuntu0.1~esm1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream fluidsynth package and not the fluidsynth package as distributed by Ubuntu. See How to fix? for Ubuntu:24.04 relevant fixed versions and status.

FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From 1.1.2 until 2.5.6, the FluidSynth command handler accepts a pitch_bend_range command whose channel argument is not bounds checked before the supplied value is written through the selected synth channel. An out-of-range channel can therefore cause an out-of-bounds heap write, leading to denial of service or possible code execution. The issue is remotely reachable when the TCP server is enabled through new_fluid_server() or fluidsynth -s, and it is locally reachable through malicious commands delivered to the FluidSynth shell on standard input. Applications that do not use the shell, command handler, or TCP server are not affected. This issue is fixed in version 2.5.6.