{"id":"UBUNTU-CVE-2026-61720","details":"FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From 2.5.0 until 2.5.6, the SF2 parser computes the DMOD modulator count as chunk.size / SF_MOD_SIZE - 1 without rejecting chunks smaller than one record. A crafted SF2 file containing a zero-sized DMOD chunk makes the unsigned subtraction wrap to UINT_MAX, and the parser then attempts billions of SFMod allocations. This exhausts process memory and causes denial of service. No workaround is available. This issue is fixed in version 2.5.6.","modified":"2026-09-24T02:00:38.900467280Z","published":"2026-09-18T20:17:00Z","upstream":["CVE-2026-61720"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-61720"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-61720"},{"type":"REPORT","url":"https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-rmc4-c8hw-455w"}],"affected":[{"package":{"name":"fluidsynth","ecosystem":"Ubuntu:14.04:LTS","purl":"pkg:deb/ubuntu/fluidsynth?arch=source&distro=trusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.1.6-2"],"ecosystem_specific":{"binaries":[{"binary_version":"1.1.6-2","binary_name":"fluidsynth"},{"binary_name":"libfluidsynth1","binary_version":"1.1.6-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-61720.json"}},{"package":{"name":"fluidsynth","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/fluidsynth?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.1.6-2build1","1.1.6-3"],"ecosystem_specific":{"binaries":[{"binary_name":"fluidsynth","binary_version":"1.1.6-3"},{"binary_name":"libfluidsynth1","binary_version":"1.1.6-3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-61720.json"}},{"package":{"name":"fluidsynth","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/fluidsynth?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.1.6-4","1.1.8-1","1.1.8-2","1.1.8-3","1.1.9-1"],"ecosystem_specific":{"binaries":[{"binary_name":"fluidsynth","binary_version":"1.1.9-1"},{"binary_name":"libfluidsynth1","binary_version":"1.1.9-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-61720.json"}},{"package":{"name":"fluidsynth","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/fluidsynth?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.1.11-4","1.1.11-4ubuntu1","2.1.0-1","2.1.1-2"],"ecosystem_specific":{"binaries":[{"binary_name":"fluidsynth","binary_version":"2.1.1-2"},{"binary_version":"2.1.1-2","binary_name":"libfluidsynth2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-61720.json"}},{"package":{"name":"fluidsynth","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/fluidsynth?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.1.7-1.1","2.2.4-2","2.2.5-1"],"ecosystem_specific":{"binaries":[{"binary_name":"fluidsynth","binary_version":"2.2.5-1"},{"binary_version":"2.2.5-1","binary_name":"libfluidsynth3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-61720.json"}},{"package":{"name":"fluidsynth","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/fluidsynth?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.3.3-2.1","2.3.4-1","2.3.4-1build1","2.3.4-1build2","2.3.4-1build3"],"ecosystem_specific":{"binaries":[{"binary_name":"fluidsynth","binary_version":"2.3.4-1build3"},{"binary_version":"2.3.4-1build3","binary_name":"libfluidsynth3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-61720.json"}},{"package":{"name":"fluidsynth","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/fluidsynth?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.4.7+dfsg-2","2.4.8+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"fluidsynth","binary_version":"2.4.8+dfsg-1"},{"binary_name":"libfluidsynth3","binary_version":"2.4.8+dfsg-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-61720.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}