{"id":"CVE-2026-61720","published":"2026-09-18T20:17:18.420","lastModified":"2026-09-24T21:25:27.050","description":"FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From 2.5.0 until 2.5.6, the SF2 parser computes the DMOD modulator count as chunk.size / SF_MOD_SIZE - 1 without rejecting chunks smaller than one record. A crafted SF2 file containing a zero-sized DMOD chunk makes the unsigned subtraction wrap to UINT_MAX, and the parser then attempts billions of SFMod allocations. This exhausts process memory and causes denial of service. No workaround is available. This issue is fixed in version 2.5.6.","cvssScore":6.2,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwes":["CWE-191"],"vendors":[],"products":[],"references":[{"url":"https://github.com/FluidSynth/fluidsynth/commit/096e1ff0d09ddcac83d94923440706f76f94bc44","tags":[]},{"url":"https://github.com/FluidSynth/fluidsynth/releases/tag/v2.5.6","tags":[]},{"url":"https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-rmc4-c8hw-455w","tags":[]}],"exploitRefs":[{"url":"https://github.com/FluidSynth/fluidsynth/commit/096e1ff0d09ddcac83d94923440706f76f94bc44","tags":[]},{"url":"https://github.com/FluidSynth/fluidsynth/releases/tag/v2.5.6","tags":[]},{"url":"https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-rmc4-c8hw-455w","tags":[]}],"hasPoc":true,"ai":null}