Use after free in fluidsynth

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2025-68617
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2025-12-23 23:15:44 UTC
Updated2026-10-19 22:10:00 UTC
DescriptionFluidSynth is a software synthesizer based on the SoundFont 2 specifications. From versions 2.5.0 to before 2.5.2, a race condition during unloading of a DLS file can trigger a heap-based use-after-free. A concurrently running thread may be pending to unload a DLS file, leading to use of freed memory, if the synthesizer is being concurrently destroyed, or samples of the (unloaded) DLS file are concurrently used to synthesize audio. This issue has been patched in version 2.5.2. The problem will not occur, when explicitly unloading a DLS file (before synth destruction), provided that at the time of unloading, no samples of the respective file are used by active voices. The problem will not occur in versions of FluidSynth that have been compiled without native DLS support.

Risk And Classification

Primary CVSS: v3.1 7 HIGH from [email protected]

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

EPSS: 0.002130000 probability, percentile 0.109590000 (date 2026-10-19)

Problem Types: CWE-416 | CWE-416 CWE-416: Use After Free

VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary7HIGHCVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
3.1[email protected]Secondary7HIGHCVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
3.1CNADECLARED7HIGHCVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

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

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

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Fluidsynth Fluidsynth All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA FluidSynth Fluidsynth affected >= 2.5.0, < 2.5.2 Not specified

References

ReferenceSourceLinkTags
github.com/FluidSynth/fluidsynth/commit/685e54cdc44911ace31774260bd0c9ec... [email protected] github.com Patch
github.com/FluidSynth/fluidsynth/commit/962b9946b5cb6b16f0c08b89dd1b7016... [email protected] github.com Patch
github.com/FluidSynth/fluidsynth/security/advisories/GHSA-ffw2-xvvp-39ch [email protected] github.com Vendor Advisory
github.com/FluidSynth/fluidsynth/issues/1728 134c704f-9b21-4f2e-91b3-4a467353bcc0 github.com Issue Tracking
github.com/FluidSynth/fluidsynth/issues/1717 134c704f-9b21-4f2e-91b3-4a467353bcc0 github.com Exploit, Issue Tracking
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

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