{"id":"CVE-2026-61714","published":"2026-09-18T20:17:18.270","lastModified":"2026-09-23T18:12:04.247","description":"FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From 2.2.4 until 2.5.6, configuring synth.midi-channels above 16 allows the MIDI player to index _fluid_player_t::channel_isplaying outside its fixed-size heap allocation while tracking active channels. The resulting out-of-bounds reads and writes invoke undefined behavior and may compromise confidentiality, integrity, or availability. No crafted MIDI file is required because the unsafe condition is created by the channel-count configuration itself. Keeping synth.midi-channels at its default value of 16 avoids the vulnerable path. This issue is fixed in version 2.5.6.","cvssScore":7.8,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","cwes":["CWE-122","CWE-125","CWE-787"],"vendors":[],"products":[],"references":[{"url":"https://github.com/FluidSynth/fluidsynth/commit/772702e00cc6acc7c607efb40283e2269211effc","tags":[]},{"url":"https://github.com/FluidSynth/fluidsynth/releases/tag/v2.5.6","tags":[]},{"url":"https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-976m-35rw-h3m6","tags":[]}],"exploitRefs":[{"url":"https://github.com/FluidSynth/fluidsynth/commit/772702e00cc6acc7c607efb40283e2269211effc","tags":[]},{"url":"https://github.com/FluidSynth/fluidsynth/releases/tag/v2.5.6","tags":[]},{"url":"https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-976m-35rw-h3m6","tags":[]}],"hasPoc":true,"ai":null}