CVE-2026-61723

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

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CVSS v3

6.8

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

CVSS v4 NEW

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not yet in upstream

VIR risk

6.8

Description

FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From 2.5.0 until 2.5.6, the native DLS parser validates ptbl chunks with the unsigned expression cues * 4 + cbsize without checking whether the multiplication and addition fit in 32 bits. A crafted DLS file can supply a large cues value that wraps the expression and passes the chunk-size check, causing poolcues.resize(cues) to request approximately four gigabytes and the parser to read billions of entries beyond the chunk boundary. The excessive allocation and invalid reads can cause denial of service. Builds with enable-native-dls set to OFF are not exposed. This issue is fixed in version 2.5.6.

Predictions

Exploit likelihood

67%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

Mitigation details

Source: Debian Security Tracker · View original ↗ · DFSG

CVE-2026-61723 NameCVE-2026-61723 Description]DLS ptbl chunk integer overflow] SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) Vulnerable and fixed packages The table below lists information on source packages. Source PackageReleaseVersionStatus fluidsynth (PTS)bullseye2.1.7-1.1fixed…

CVE-2026-61723

Name	CVE-2026-61723
Description	]DLS ptbl chunk integer overflow]
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
fluidsynth (PTS)	bullseye	2.1.7-1.1	fixed
	bookworm	2.3.1-2	fixed
	trixie	2.4.4+dfsg-1+deb13u2	fixed
	forky, sid	2.5.6+dfsg-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version
fluidsynth	source	bullseye	(not affected)
fluidsynth	source	bookworm	(not affected)
fluidsynth	source	trixie	(not affected)
fluidsynth	source	(unstable)	2.5.6+dfsg-1

Notes

[trixie] - fluidsynth <not-affected> (Vulnerable code introduced later)
[bookworm] - fluidsynth <not-affected> (Vulnerable code introduced later)
[bullseye] - fluidsynth <not-affected> (Vulnerable code introduced later)
https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-r4mc-v3p8-pv47
Introduced with: https://github.com/FluidSynth/fluidsynth/commit/c959f8d208bbad9e396dfb745285806b5a4c5a07 (v2.5.0)
Fixed by: https://github.com/FluidSynth/fluidsynth/commit/a2ab32b9c3b9f8845b7254adea73c211f6c5a24c (v2.5.6)

Home - Debian Security - Source (Git)

Apply commands

text fix

Notes

[trixie] - fluidsynth <not-affected> (Vulnerable code introduced later)[bookworm] - fluidsynth <not-affected> (Vulnerable code introduced later)[bullseye] - fluidsynth <not-affected> (Vulnerable code introduced later)https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-r4mc-v3p8-pv47Introduced with: https://github.com/FluidSynth/fluidsynth/commit/c959f8d208bbad9e396dfb745285806b5a4c5a07 (v2.5.0)Fixed by: https://github.com/FluidSynth/fluidsynth/commit/a2ab32b9c3b9f8845b7254adea73c211f6c5a24c (v2.5.6)

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-190

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

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