{"id":"CVE-2026-61721","summary":"FluidSynth: Heap-based buffer overrun for DLS samples","details":"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.","aliases":["GHSA-59ph-rx8r-8p4j"],"modified":"2026-09-19T11:45:32.325271702Z","published":"2026-09-18T20:00:29.403Z","database_specific":{"cwe_ids":["CWE-122","CWE-125"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61721.json","cna_assigner":"GitHub_M"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61721.json"},{"type":"FIX","url":"https://github.com/FluidSynth/fluidsynth/commit/2354c2a9acdb26de7cdcd37c903ee108f46c0a7d"},{"type":"WEB","url":"https://github.com/FluidSynth/fluidsynth/releases/tag/v2.5.6"},{"type":"ADVISORY","url":"https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-59ph-rx8r-8p4j"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-61721"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/fluidsynth/fluidsynth","events":[{"introduced":"df432e151dcaf463b1ecc7e873803bfa19733fd3"},{"fixed":"e5b11058a619246cea42976dacb76ca54be3d45d"}],"database_specific":{"extracted_events":[{"introduced":"2.5.0"},{"fixed":"2.5.6"}],"source":"AFFECTED_FIELD"}}],"versions":["v2.5.5","v2.5.4","v2.5.3","v2.5.2","v2.5.1","v2.5.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-61721.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:H/I:L/A:H"}]}