CVE-2021-21417
CVE-2021-21417 is a high-severity vulnerability in Fluidsynth with a CVSS 3.x base score of 7.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-416.
Key facts
- Severity: High (CVSS 3.x base score 7.2)
- CVSS v2: 4.3
- EPSS exploit prediction: 1% (57th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-416
- Affected product: Fluidsynth
- Published:
- Last modified:
Description
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.
Frequently asked questions
- What is CVE-2021-21417?
- 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.
- How severe is CVE-2021-21417?
- CVE-2021-21417 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over local access with high attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
- Is CVE-2021-21417 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-21417?
- CVE-2021-21417 primarily affects Fluidsynth. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2021-21417?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2021-21417 published?
- CVE-2021-21417 was published on 2021-04-29 and last updated on 2026-06-17.
References
- https://github.com/FluidSynth/fluidsynth/issues/808
- https://github.com/FluidSynth/fluidsynth/pull/810
- https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-6fcq-pxhc-jxc9
- https://lists.debian.org/debian-lts-announce/2021/06/msg00027.html
Affected products (2)
- cpe:2.3:a:fluidsynth:fluidsynth:*:*:*:*:*:*:*:*
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
More vulnerabilities in Fluidsynth
- CVE-2025-56225 — High (CVSS 7.5): fluidsynth-2.4.6 and earlier versions is vulnerable to Null pointer dereference in fluid_synth_monopoly.c, that can be…
- CVE-2025-68617 — High (CVSS 7.0): FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From versions 2.5.0 to before 2.5.2, a…
All CVEs affecting Fluidsynth →
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