Use after free in fluidsynth_CVE-2025-68617

7 / 10

HIGH

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

Description

FluidSynth 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.

Basic Information

ID CVE-2025-68617

Source GitHub_M

Published Dec 23, 2025 at 22:41

Affected Product

Vendor FluidSynth

Product fluidsynth

Version >= 2.5.0, < 2.5.2

Affected Versions FluidSynth fluidsynth >= 2.5.0, < 2.5.2

CWE Classification

CWE-416

References

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    "published": "2025-12-23T22:41:28.861Z",
    "modified": "2025-12-23T22:41:28.861Z",
    "type": "cve",
    "title": "Use after free in fluidsynth",
    "source": "GitHub_M",
    "references": "https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-ffw2-xvvp-39ch\nhttps://github.com/FluidSynth/fluidsynth/issues/1717\nhttps://github.com/FluidSynth/fluidsynth/issues/1728\nhttps://github.com/FluidSynth/fluidsynth/commit/685e54cdc44911ace31774260bd0c9ec89887491\nhttps://github.com/FluidSynth/fluidsynth/commit/962b9946b5cb6b16f0c08b89dd1b7016d4fce886",
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