Heap-based Buffer Overflow Affecting fluidsynth package, versions <2.5.6+dfsg-1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-DEBIANUNSTABLE-FLUIDSYNTH-18292053
- published24 Jul 2026
- disclosed18 Sept 2026
Introduced: 24 Jul 2026
CVE-2026-61721 (opens in a new tab)How to fix?
Upgrade Debian:unstable fluidsynth to version 2.5.6+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 2.5.0 until 2.5.6, the native DLS loader assigns file-controlled wsmp.loop_start and wsmp.loop_length values to samples without calling fluid_sample_validate() or fluid_sample_sanitize_loop(). A crafted DLS file can place sample loop points beyond the sample buffer, causing out-of-bounds reads during audio rendering, undefined behavior, possible memory disclosure, and denial of service. Builds compiled with the CMake option enable-native-dls set to OFF do not expose the affected parser. This issue is fixed in version 2.5.6.