{"id":"CVE-2026-58264","published":"2026-09-18T20:17:18.107","lastModified":"2026-09-24T21:25:27.050","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.","cvssScore":9.8,"cvssSeverity":"CRITICAL","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwes":["CWE-122"],"vendors":[],"products":[],"references":[{"url":"https://github.com/FluidSynth/fluidsynth/commit/762a3bd39a431cd45abf3bbcce7286c87909d087","tags":[]},{"url":"https://github.com/FluidSynth/fluidsynth/pull/1796","tags":[]},{"url":"https://github.com/FluidSynth/fluidsynth/releases/tag/v2.5.6","tags":[]},{"url":"https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-mqmq-w63q-cj94","tags":[]}],"exploitRefs":[{"url":"https://github.com/FluidSynth/fluidsynth/commit/762a3bd39a431cd45abf3bbcce7286c87909d087","tags":[]},{"url":"https://github.com/FluidSynth/fluidsynth/pull/1796","tags":[]},{"url":"https://github.com/FluidSynth/fluidsynth/releases/tag/v2.5.6","tags":[]},{"url":"https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-mqmq-w63q-cj94","tags":[]}],"hasPoc":true,"ai":{"summary":"FluidSynth versions from 1.1.2 to 2.5.5 are vulnerable to out-of-bounds heap write due to unbounded channel argument in pitch_bend_range command, leading to potential code execution or denial of service.","exploitability":"Exploitation is moderately hard requiring either a TCP server to be enabled or direct shell commands, making it less likely in unmodified deployments.","blast_radius":"If exploited, the vulnerability could lead to remote code execution or denial of service, impacting systems using the affected FluidSynth versions.","remediation":"Upgrade to FluidSynth version 2.5.6 or later.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["rce","heap-write","remote-exploit","synth"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-09-27T09:01:33.310Z"}}