CVE catalog
CVE-2026-61720
fluidsynth: CVE-2026-61720
- Severity
- Medium · CVSS 6.2
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.18% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | fluidsynth | sid | 2.6.1+dfsg-2 | fixed |
| Debian | fluidsynth | forky | 2.6.1+dfsg-2 | fixed |
| Debian | fluidsynth | trixie | 2.4.4+dfsg-1+deb13u3 | not affected |
| Debian | fluidsynth | bookworm | 2.3.1-2 | not affected |
| Ubuntu | fluidsynth | pro | 2.4.7+dfsg-2 | vulnerable |
| Ubuntu | fluidsynth | pro | 2.4.8+dfsg-1 | vulnerable |
| Ubuntu | fluidsynth | pro | 2.4.8+dfsg-1ubuntu0.1~esm1 | vulnerable |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | fluidsynth | source | sid | 2.5.6+dfsg-1 | not yet assigned | Not reported | Not reported |
| Debian | fluidsynth | source | forky | 2.5.6+dfsg-1 | not yet assigned | Not reported | Not reported |
| Debian | fluidsynth | source | trixie | Not affected | unimportant | Not reported | Not reported |
| Debian | fluidsynth | source | bookworm | Not affected | unimportant | Not reported | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [fluidsynth]Not affected
Details (2)
2.3.1-2· amd64 · bookwormNot affected
dsa · fluidsynth · debian · bookworm
2.3.1-2· arm64 · bookwormNot affected
dsa · fluidsynth · debian · bookworm
- [libfluidsynth3]Not affected
Source package: [fluidsynth]
Details (2)
2.3.1-2· amd64 · bookwormNot affected
dsa · fluidsynth · debian · bookworm
2.3.1-2· arm64 · bookwormNot affected
dsa · fluidsynth · debian · bookworm
- [libfluidsynth-dev]Not affected
Source package: [fluidsynth]
Details (2)
2.3.1-2· amd64 · bookwormNot affected
dsa · fluidsynth · debian · bookworm
2.3.1-2· arm64 · bookwormNot affected
dsa · fluidsynth · debian · bookworm
Observed:
References
- [https://nvd.nist.gov/vuln/detail/CVE-2026-61720]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-61720]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2026-61720]
- [https://security-tracker.debian.org/tracker/CVE-2026-61720]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-61720.json]
[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]