TI-2026-44179 Aliases CVE-2026-61721

FluidSynth: Heap-based buffer overrun for DLS samples

LOW 34CWE-122Published 2026-09-18 · Updated 2026-09-18

Key facts

Attack vector: Local
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: High · Low · High
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00192 8th percentileScored 2026-11-07

Fix Fixed fluidsynth (FluidSynth): 2.5.6

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
FluidSynth	fluidsynth	2.5.0 to before 2.5.6	2.5.6	Patch available	CNA

fluidsynth VendorFluidSynth Affected 2.5.0 to before 2.5.6 Fixed in 2.5.6 Patch available CNA

Remediation

Fix · CNA fluidsynth (FluidSynth) Fixed in 2.5.6

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product

Red Hat

Timeline

2026-10-02 Threatist record created from CVE-2026-61721

References

Other 3

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
TI-2026-74907 Out-of-bounds write in FluidSynth SoundFont modulator handling CVSS 4.0MEDIUM 6.9
TI-2026-41957 FluidSynth: Heap-based buffer overrun CVSS 3.1CRITICAL 9.8
TI-2026-44176 FluidSynth: Heap Buffer Overflow in MIDI Player CVSS 3.1HIGH 7.8
TI-2021-04515 Use after free in fluidsynth CVSS 3.1HIGH 7.2

See all 9 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences