FluidSynth: Heap-based buffer overrun

Summary

CVECVE-2026-58264
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-18 20:17:18 UTC
Updated2026-09-24 21:25:27 UTC
DescriptionFluidSynth 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.

Risk And Classification

Primary CVSS: v3.1 9.8 CRITICAL from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS: 0.008010000 probability, percentile 0.547770000 (date 2026-09-25)

Problem Types: CWE-122 | CWE-122 CWE-122: Heap-based Buffer Overflow


VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
3.1CNADECLARED9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA FluidSynth Fluidsynth affected >= 1.1.2, < 2.5.6 Not specified

References

ReferenceSourceLinkTags
github.com/FluidSynth/fluidsynth/releases/tag/v2.5.6 [email protected] github.com
github.com/FluidSynth/fluidsynth/security/advisories/GHSA-mqmq-w63q-cj94 [email protected] github.com
github.com/FluidSynth/fluidsynth/commit/762a3bd39a431cd45abf3bbcce7286c8... [email protected] github.com
github.com/FluidSynth/fluidsynth/pull/1796 [email protected] github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

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