CVE-2026-61720
6.2
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From 2.5.0 until 2.5.6, the SF2 parser computes the DMOD modulator count as chunk.size / SF_MOD_SIZE - 1 without rejecting chunks smaller than one record. A crafted SF2 file containing a zero-sized DMOD chunk makes the unsigned subtraction wrap to UINT_MAX, and the parser then attempts billions of SFMod allocations. This exhausts process memory and causes denial of service. No workaround is available. This issue is fixed in version 2.5.6.
Affected Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| FluidSynth | fluidsynth | >= 2.5.0, < 2.5.6 | affected |
Weaknesses
- CWE-191: CWE-191: Integer Underflow (Wrap or Wraparound)
References
- https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-rmc4-c8hw-455w
- https://github.com/FluidSynth/fluidsynth/commit/096e1ff0d09ddcac83d94923440706f76f94bc44
- https://github.com/FluidSynth/fluidsynth/releases/tag/v2.5.6
Feedback
Was this page helpful?
Glad to hear it! Please tell us how we can improve.
Sorry to hear that. Please tell us how we can improve.