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Vulnerability record · CVE-2021-21417 · published 29 April 2021

CVE-2021-21417: Fluidsynth use after free vulnerability

FFluidsynth · Fluidsynth

fluidsynth is a software synthesizer based on the SoundFont 2 specifications. A use after free violation was discovered in fluidsynth, that can be triggered when loading an invalid SoundFont file.

5.5 CVSS 3.1 Medium EPSS 0.94% · top 40.5% CWE-416 · Use after free
5.5CVSS 3.1 base score, v2 4.3
0.94%EPSS exploitation probability, 30 days
NoNot in CISA KEV
2Affected product versions listed by NVD
8References, 4 tagged exploit
17 Jun 2026Last modified by NVD

Description

fluidsynth is a software synthesizer based on the SoundFont 2 specifications. A use after free violation was discovered in fluidsynth, that can be triggered when loading an invalid SoundFont file.

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

Affected products

2 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/FluidSynth/fluidsynth/issues/808 ExploitThird Party Advisory
https://github.com/FluidSynth/fluidsynth/pull/810 ExploitIssue TrackingPatchThird Party Advisory
https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-6fcq-pxhc-jxc9 Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00027.html Mailing ListThird Party Advisory
https://github.com/FluidSynth/fluidsynth/issues/808 ExploitThird Party Advisory
https://github.com/FluidSynth/fluidsynth/pull/810 ExploitIssue TrackingPatchThird Party Advisory
https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-6fcq-pxhc-jxc9 Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00027.html Mailing ListThird Party Advisory

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Source: NIST National Vulnerability Database (record CVE-2021-21417), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.