Use After Free Affecting fluidsynth package, versions <2.5.2+dfsg-1


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.21% (12th percentile)

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  • Snyk IDSNYK-DEBIANUNSTABLE-FLUIDSYNTH-14578133
  • published25 Dec 2025
  • disclosed23 Dec 2025

Introduced: 23 Dec 2025

CVE-2025-68617  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Debian:unstable fluidsynth to version 2.5.2+dfsg-1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream fluidsynth package and not the fluidsynth package as distributed by Debian. See How to fix? for Debian:unstable relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1