CVE-2026-61714 FluidSynth: Heap Buffer Overflow in MIDI Player
Heap buffer overflow in FluidSynth MIDI player allows code execution or denial of service when synth.midi-channels is configured above 16.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-61714?
CVE-2026-61714 is a high-severity memory corruption vulnerability in fluidsynth, published on 18 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From 2.2.4 until 2.5.6, configuring synth.midi-channels above 16 allows the MIDI player to index _fluid_player_t::channel_isplaying outside its fixed-size heap allocation while tracking active channels. The resulting out-of-bounds reads and writes invoke undefined behavior and may compromise confidentiality, integrity, or availability. No crafted MIDI file is required because the unsafe condition is created by the channel-count configuration itself. Keeping synth.midi-channels at its default value of 16 avoids the vulnerable path. This issue is fixed in version 2.5.6.
Which versions are affected by CVE-2026-61714?
How do I fix CVE-2026-61714?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-61714 being exploited?
There is no known exploitation of CVE-2026-61714 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-61714, ECHO-586f-1d4c-181d, GHSA-976m-35rw-h3m6, OESA-2026-3165, OESA-2026-3166, OESA-2026-3168 and 1 more.