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.
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Affected Vendors & Products
Advisories
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Fixes
Solution
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Workaround
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References
History
Tue, 23 Dec 2025 23:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | Use after free in fluidsynth | |
| Weaknesses | CWE-416 | |
| References |
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| Metrics |
cvssV3_1
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2025-12-23T22:41:28.861Z
Reserved: 2025-12-19T14:58:47.825Z
Link: CVE-2025-68617
No data.
Status : Received
Published: 2025-12-23T23:15:44.757
Modified: 2025-12-23T23:15:44.757
Link: CVE-2025-68617
No data.
OpenCVE Enrichment
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Weaknesses