CVE-2026-61721

FluidSynth: Heap-based buffer overrun for DLS samples

HIGH
8
CVSS Score
Published: September 18, 2026 at 08:00 PM UTC
Updated: September 23, 2026 at 06:30 PM UTC
1 product affected across 1 vendorFluidSynth

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Severity
HIGH8
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From 2.5.0 until 2.5.6, the native DLS loader assigns file-controlled wsmp.loop_start and wsmp.loop_length values to samples without calling fluid_sample_validate() or fluid_sample_sanitize_loop(). A crafted DLS file can place sample loop points beyond the sample buffer, causing out-of-bounds reads during audio rendering, undefined behavior, possible memory disclosure, and denial of service. Builds compiled with the CMake option enable-native-dls set to OFF do not expose the affected parser. This issue is fixed in version 2.5.6.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.5.6
Affected range stops below 2.5.6, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8HIGHGitHub_M
Attack Vector
LOCAL
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
LOW
Availability
HIGH
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-122CWE-125

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