CVE-2025-68617

HIGH EPSS 7.6%
Published Dec 23, 20256mo ago · Modified Jun 17, 20262w ago
7.0 CVSS 3.1
High
Find Similar
Published Dec 23, 2025 6mo ago
Last Modified Jun 17, 2026 2w ago

Description

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 of unloading, no samples of the respective file are used by active voices. The problem will not occur in versions of FluidSynth that have been compiled without native DLS support.

CVSS Details

Base Score
7.0
Exploitability
1.0
Impact
5.9
Vector string
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack Vector Local
Attack Complexity High
Privileges Required None
User Interaction Required
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
7.6% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-416 Use After Free Memory Safety

Affected Products 1

VendorProductVersionRange
fluidsynthfluidsynth*≥2.5.0  –  <2.5.2

References 5

  • github.com https://github.com/FluidSynth/fluidsynth/commit/685e54cdc44911ace31774260bd0c9ec89887491
    Patch
  • github.com https://github.com/FluidSynth/fluidsynth/commit/962b9946b5cb6b16f0c08b89dd1b7016d4fce886
    Patch
  • github.com https://github.com/FluidSynth/fluidsynth/issues/1717
    ExploitIssue Tracking
  • github.com https://github.com/FluidSynth/fluidsynth/issues/1728
    Issue Tracking
  • github.com https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-ffw2-xvvp-39ch
    Vendor Advisory

Remediation

  • github.com https://github.com/FluidSynth/fluidsynth/commit/685e54cdc44911ace31774260bd0c9ec89887491
    Patch
  • github.com https://github.com/FluidSynth/fluidsynth/commit/962b9946b5cb6b16f0c08b89dd1b7016d4fce886
    Patch