CVE catalog

CVE-2026-58264

FluidSynth vulnerabilities

Severity: Critical · CVSS 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: Jul 8, 2026, 12:00:00 AM UTC
Source: [NVD] · [CVE record]
EPSS: 0.59% · Oct 25, 2026

FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From 1.1.2 until 2.5.6, the FluidSynth command handler accepts a pitch_bend_range command whose channel argument is not bounds checked before the supplied value is written through the selected synth channel. An out-of-range channel can therefore cause an out-of-bounds heap write, leading to denial of service or possible code execution. The issue is remotely reachable when the TCP server is enabled through new_fluid_server() or fluidsynth -s, and it is locally reachable through malicious commands delivered to the FluidSynth shell on standard input. Applications that do not use the shell, command handler, or TCP server are not affected. 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`	fixed
Debian	fluidsynth	bookworm	`2.3.1-2`	vulnerable
Ubuntu	fluidsynth	noble	`2.3.4-1ubuntu0.1~esm1`	fixed
Ubuntu	libfluidsynth-dev	noble	`2.3.4-1ubuntu0.1~esm1`	fixed
Ubuntu	libfluidsynth3	noble	`2.3.4-1ubuntu0.1~esm1`	fixed
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`	fixed
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`	fixed
Opensuse	fluidsynth	tumbleweed	`2.5.6-1.1`	fixed

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	`2.4.4+dfsg-1+deb13u3`	not yet assigned	Not reported	Not reported
Debian	fluidsynth	source	bookworm	`(unfixed)`	not yet assigned	Not reported	Not reported
Ubuntu	fluidsynth	deb	noble	`2.3.4-1ubuntu0.1~esm1`	Not reported	Not reported	Not reported
Ubuntu	libfluidsynth-dev	deb	noble	`2.3.4-1ubuntu0.1~esm1`	Not reported	Not reported	Not reported
Ubuntu	libfluidsynth3	deb	noble	`2.3.4-1ubuntu0.1~esm1`	Not reported	Not reported	Not reported
Ubuntu	fluidsynth	deb	pro	`2.4.8+dfsg-1ubuntu0.1~esm1`	Not reported	USN-8885-1	Not reported
Ubuntu	fluidsynth	deb	pro	`2.4.8+dfsg-1ubuntu0.1~esm1`	Not reported	UBUNTU-CVE-2026-58264	Not reported
Opensuse	fluidsynth	rpm	tumbleweed	`2.5.6-1.1`	Not reported	OPENSUSE-SU-2026:11211-1	Not reported

Notes

[bookworm] fluidsynth: Only reachable via the fluidsynth shell or TCP command server, which already grants unauthenticated control; one-line fix can ride a future upload

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[fluidsynth]Affected
Details (2)
- 2.3.1-2 · amd64 · bookworm
  Affected
  usn · fluidsynth · debian · bookworm; usn · fluidsynth · debian · 12
- 2.3.1-2 · arm64 · bookworm
  Affected
  usn · fluidsynth · debian · bookworm; usn · fluidsynth · debian · 12
[libfluidsynth3]Affected
Source package: [fluidsynth]
Details (2)
- 2.3.1-2 · amd64 · bookworm
  Affected
  usn · fluidsynth · debian · bookworm; usn · fluidsynth · debian · 12
- 2.3.1-2 · arm64 · bookworm
  Affected
  usn · fluidsynth · debian · bookworm; usn · fluidsynth · debian · 12
[libfluidsynth-dev]Affected
Source package: [fluidsynth]
Details (2)
- 2.3.1-2 · amd64 · bookworm
  Affected
  usn · fluidsynth · debian · bookworm; usn · fluidsynth · debian · 12
- 2.3.1-2 · arm64 · bookworm
  Affected
  usn · fluidsynth · debian · bookworm; usn · fluidsynth · debian · 12

[Debian 13 (Trixie)]

[fluidsynth]Affected
Details (2)
- 2.4.4+dfsg-1+deb13u2 · amd64 · trixie
  Affected · Fixed: 2.4.4+dfsg-1+deb13u3
  usn · fluidsynth · debian · 13
- 2.4.4+dfsg-1+deb13u2 · arm64 · trixie
  Affected · Fixed: 2.4.4+dfsg-1+deb13u3
  usn · fluidsynth · debian · 13
[libfluidsynth3]Affected
Source package: [fluidsynth]
Details (2)
- 2.4.4+dfsg-1+deb13u2 · amd64 · trixie
  Affected · Fixed: 2.4.4+dfsg-1+deb13u3
  usn · fluidsynth · debian · 13
- 2.4.4+dfsg-1+deb13u2 · arm64 · trixie
  Affected · Fixed: 2.4.4+dfsg-1+deb13u3
  usn · fluidsynth · debian · 13
[libfluidsynth-dev]Affected
Source package: [fluidsynth]
Details (2)
- 2.4.4+dfsg-1+deb13u2 · amd64 · trixie
  Affected · Fixed: 2.4.4+dfsg-1+deb13u3
  usn · fluidsynth · debian · 13
- 2.4.4+dfsg-1+deb13u2 · arm64 · trixie
  Affected · Fixed: 2.4.4+dfsg-1+deb13u3
  usn · fluidsynth · debian · 13

[openSUSE Tumbleweed]

[fluidsynth-devel]Unknown
Source package: [fluidsynth]
Details (1)
- 2.5.7-1.1 · x86_64 · tumbleweed
  Unknown · Fixed: 2.5.6-1.1
  Version impact unknown
  usn · fluidsynth · opensuse · tumbleweed
[libfluidsynth3]Unknown
Source package: [fluidsynth]
Details (1)
- 2.5.7-1.1 · x86_64 · tumbleweed
  Unknown · Fixed: 2.5.6-1.1
  Version impact unknown
  usn · fluidsynth · opensuse · tumbleweed
[libfluidsynth3-32bit]Unknown
Source package: [fluidsynth]
Details (1)
- 2.5.7-1.1 · x86_64 · tumbleweed
  Unknown · Fixed: 2.5.6-1.1
  Version impact unknown
  usn · fluidsynth · opensuse · tumbleweed
[fluidsynth]Fixed
Source package: [fluidsynth]
Details (1)
- 2.5.7-1.1 · x86_64 · tumbleweed
  Fixed · Fixed: 2.5.6-1.1
  usn · fluidsynth · opensuse · tumbleweed

Observed: Oct 23, 2026, 9:44:26 PM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX] · [Ubuntu Security Notices (USN)]