CVE-2025-68617
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.21%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.0 HIGHCVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
- EPSS
- 0.21% probability · 11th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- fluidsynth/fluidsynth
- Source
- security-advisories@github.com
References
- https://github.com/FluidSynth/fluidsynth/commit/685e54cdc44911ace31774260bd0c9ec89887491Patch
- https://github.com/FluidSynth/fluidsynth/commit/962b9946b5cb6b16f0c08b89dd1b7016d4fce886Patch
- https://github.com/FluidSynth/fluidsynth/issues/1717Exploit, Issue Tracking
- https://github.com/FluidSynth/fluidsynth/issues/1728Issue Tracking
- https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-ffw2-xvvp-39chVendor Advisory
- https://github.com/FluidSynth/fluidsynth/issues/1717Exploit, Issue Tracking
- https://github.com/FluidSynth/fluidsynth/issues/1728Issue Tracking
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.