Use after free in fluidsynth
Priority LOW 33CWE-416Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- Required
- Attack complexity
- High
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-416 and the CVSS impact.
Summary
fluidsynth is a software synthesizer based on the SoundFont 2 specifications. A use after free violation was discovered in fluidsynth, that can be triggered when loading an invalid SoundFont file.
Why it matters now
EPSS 0.00944 61st percentileScored 2026-11-07
Public exploit Yes 2 exploit referencesTagged by NVD
Fix Fixed fluidsynth (FluidSynth): 2.1.8
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| FluidSynth | fluidsynth | before 2.1.8 | 2.1.8 | Patch available | CNA |
- fluidsynth VendorFluidSynth Affected before 2.1.8 Fixed in 2.1.8 Patch available CNA
CPE configurations NVD · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:fluidsynth:fluidsynth:*:*:*:*:*:*:*:* | before 2.1.8 | Vulnerable | FluidSynth |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Debian |
- cpe:2.3:a:fluidsynth:fluidsynth:*:*:*:*:*:*:*:* Versions before 2.1.8 Vulnerable ·FluidSynth
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
Remediation
- Fix · CNA fluidsynth (FluidSynth) Fixed in 2.1.8
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2021-21417
References
More Fluidsynth vulnerabilities
- TI-2025-35279 fluidsynth-2.4.6 and earlier versions is vulnerable to Null pointer dereference in… CVSS 3.1HIGH 7.5
- TI-2025-42135 Use after free in fluidsynth CVSS 3.1HIGH 7.0
Sources
- CVE-2021-21417 · CVE Program
- CVE-2021-21417 · NVD
- FIRST EPSS
- CVE-2021-21417 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences