CVE-2026-61721

high

Published 2026-09-18 · Modified 2026-09-18

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CVSS v3

8.0

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H

CVSS v4 NEW

—

not yet in upstream

VIR risk

8.0

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.

Predictions

Exploit likelihood

77%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

OS impact

Debian Fixed 5 releases

Version	Status	Fixed in
trixie	Fixed	`0`
sid	Fixed	`2.5.6+dfsg-1`
forky	Fixed	`2.5.6+dfsg-1`
bullseye	Fixed	`0`
bookworm	Fixed	`0`

References

CWEs

CWE-122 CWE-125

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.