Fluidsynth: From 2.5.0 until 2.5.6, the native DLS parser validates articulation chunks using the unsigned expression
Affects fluidsynthSource GCVE Database
Not known to be exploited · CVSS 6.8 Medium · fixed in 2.5.6 : update fluidsynth when convenient.
Data as of 6 Nov 2026, 23:24 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 2.5.6
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:HExploitation evidence
Disclosed: evidence found.
CVE published 18 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 7 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSfluidsynthpkg:deb/ubuntu/fluidsynth?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu Pro 26.04 LTSfluidsynthpkg:deb/ubuntu/fluidsynth?arch=source&distro=esm-apps/resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSfluidsynthpkg:deb/ubuntu/fluidsynth?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu Pro 24.04 LTSfluidsynthpkg:deb/ubuntu/fluidsynth?arch=source&distro=esm-apps/nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSfluidsynthpkg:deb/ubuntu/fluidsynth?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu Pro 22.04 LTSfluidsynthpkg:deb/ubuntu/fluidsynth?arch=source&distro=esm-apps/jammyOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade FluidSynth to version 2.5.6 or later where this issue is fixed. Alternatively, disable the native DLS parser by building FluidSynth with the CMake option enable-native-dls set to OFF, which prevents exposure to this vulnerability.
Description
FluidSynth versions from 2.5.0 up to but not including 2.5.6 contain a vulnerability in the native DLS parser where an integer overflow in the validation of articulation chunks allows a crafted DLS file to bypass chunk-size checks. This leads to excessive processing and invalid memory reads, causing a denial of service. The issue does not affect builds with the native DLS parser disabled via the CMake option enable-native-dls=OFF. The vulnerability is fixed in version 2.5.6.