Vulnerability · Published Sep 18, 2026 · Assigned by GitHub_M
CVE-2026-61722FluidSynth: DLS Articulation Chunk Integer Overflow
Medium 6.8
In plain English
A medium-severity integer overflow in fluidsynth from FluidSynth. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:14 | fluidsynth | 2.5.6+dfsg-1 | DEBIAN-CVE-2026-61722 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| FluidSynth | fluidsynth | >= 2.5.0, < 2.5.6 |
Weakness: CWE-190 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H