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.

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History

Mon, 21 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Sun, 20 Sep 2026 00:15:00 +0000

Type Values Removed Values Added
First Time appeared Fluidsynth
Fluidsynth fluidsynth
Vendors & Products Fluidsynth
Fluidsynth fluidsynth

Fri, 18 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
Description 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.
Title FluidSynth: Heap-based buffer overrun
Weaknesses CWE-122
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-21T20:47:56.341Z

Reserved: 2026-06-29T21:54:30.331Z

Link: CVE-2026-58264

cve-icon Vulnrichment

Updated: 2026-09-21T20:44:18.258Z

cve-icon NVD

Status : Deferred

Published: 2026-09-18T20:17:18.107

Modified: 2026-09-24T21:25:27.050

Link: CVE-2026-58264

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-20T00:00:12Z

Weaknesses