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Vulnerabilities

Security fix · CVE-2025-68617

FluidSynth is a software synthesizer based on the SoundFont 2 specifications.

Published Dec 23, 2025 · catalog updated Dec 24, 2025 · FluidSynth

Last checked Nov 2, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2025-68617. EPSS is 0.21%. Act only if a listed version of FluidSynth is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.0
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.21%
Remediation
Version ranges on file
Affected products
vendor FluidSynth fluidsynth 2.5.0, < 2.5.2

FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From versions 2.5.0 to before 2.5.2, a race condition during unloading of a DLS file can trigger a heap-based use-after-free. A concurrently running thread may be pending to unload a DLS file, leading to use of freed memory, if the synthesizer is being concurrently destroyed, or samples of the (unloaded) DLS file are concurrently used to synthesize audio. This issue has been patched in version 2.5.2. The problem will not occur, when explicitly unloading a DLS file (before synth destruction), provided that at the time

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor FluidSynth fluidsynth 2.5.0, < 2.5.22.5.0, < 2.5.2

How to fix CVE-2025-68617

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2025-68617. EPSS is 0.21%. Act only if a listed version of FluidSynth is installed.

Which versions are affected?

Compare what you have installed with FluidSynth fluidsynth 2.5.0, < 2.5.2 2.5.0, < 2.5.2. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.21%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Dec 23, 2025 · EUVD

    Detected

    FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From versions 2.5.0 to before 2.5.2, a race condition during unloading of a DLS file can trigger a heap-based use-after-free. A concurrently running thread may be pending to unload a DLS file, leading to use of freed memory, if the synthesizer is being concurrently destroyed, or samples of the (unloaded) DLS file are con

  2. Dec 24, 2025 · EUVD

    Updated

    FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From versions 2.5.0 to before 2.5.2, a race condition during unloading of a DLS file can trigger a heap-based use-after-free. A concurrently running thread may be pending to unload a DLS file, leading to use of freed memory, if the synthesizer is being concurrently destroyed, or samples of the (unloaded) DLS file are con

Sources

  • CVE.orgVulnerability recordCVE-2025-68617

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2025-68617

    30-day exploitation probability 0.21%

    first.org
  • EUVDVulnerability recordEUVD-2025-205027

    FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From versions 2.5.0 to before 2.5.2, a race condition during unloading of a DLS file can trigger a heap-based use-after-free. A concurrently running thread may be pending to unload a DLS file, leading t

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Nov 2, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSNov 2, 2026
  • CVE.orgNov 2, 2026
  • EUVDNov 1, 2026