CVE-2026-61722 FluidSynth: DLS Articulation Chunk Integer Overflow
A crafted DLS file triggers an integer overflow in FluidSynth's native parser, causing denial of service via excessive processing.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-61722?
CVE-2026-61722 is a medium-severity vulnerability in fluidsynth, published on 18 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From 2.5.0 until 2.5.6, the native DLS parser validates articulation chunks using the unsigned expression cbsize + connblocks * 12 without first ensuring that the multiplication and addition fit in 32 bits. A crafted DLS file can supply a large connblocks value that wraps the expression and bypasses the chunk-size check, after which the parser performs approximately one billion 12-byte iterations beyond the chunk boundary. The excessive processing and invalid reads can cause denial of service. Builds with the CMake option enable-native-dls set to OFF do not expose the parser. This issue is fixed in version 2.5.6.
Weakness: CWE-190
Which versions are affected by CVE-2026-61722?
How do I fix CVE-2026-61722?
Upgrade to a fixed version.
Is CVE-2026-61722 being exploited?
There is no known exploitation of CVE-2026-61722 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-61722, GHSA-hp72-35pr-6h6r, UBUNTU-CVE-2026-61722.