Vulnerability · Published Sep 18, 2026 · Assigned by GitHub_M
CVE-2026-61723FluidSynth: DLS ptbl 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 8% 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 ptbl chunks with the unsigned expression cues * 4 + cbsize without checking whether the multiplication and addition fit in 32 bits. A crafted DLS file can supply a large cues value that wraps the expression and passes the chunk-size check, causing poolcues.resize(cues) to request approximately four gigabytes and the parser to read billions of entries beyond the chunk boundary. The excessive allocation and invalid reads can cause denial of service. Builds with enable-native-dls set to OFF are not exposed. 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-2026-61723 |
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