{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-61720", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-07-10T18:51:13.920Z", "datePublished": "2026-09-18T20:03:43.989Z", "dateUpdated": "2026-09-18T20:03:43.989Z"}, "containers": {"cna": {"title": "FluidSynth: SF2 DMOD Chunk Unsigned Underflow", "problemTypes": [{"descriptions": [{"cweId": "CWE-191", "lang": "en", "description": "CWE-191: Integer Underflow (Wrap or Wraparound)", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 6.2, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-rmc4-c8hw-455w", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-rmc4-c8hw-455w"}, {"name": "https://github.com/FluidSynth/fluidsynth/commit/096e1ff0d09ddcac83d94923440706f76f94bc44", "tags": ["x_refsource_MISC"], "url": "https://github.com/FluidSynth/fluidsynth/commit/096e1ff0d09ddcac83d94923440706f76f94bc44"}, {"name": "https://github.com/FluidSynth/fluidsynth/releases/tag/v2.5.6", "tags": ["x_refsource_MISC"], "url": "https://github.com/FluidSynth/fluidsynth/releases/tag/v2.5.6"}], "affected": [{"vendor": "FluidSynth", "product": "fluidsynth", "versions": [{"version": ">= 2.5.0, < 2.5.6", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-09-18T20:03:43.989Z"}, "descriptions": [{"lang": "en", "value": "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."}], "source": {"advisory": "GHSA-rmc4-c8hw-455w", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "fluidsynth", "vendor": "FluidSynth", "versions": [{"status": "affected", "version": ">= 2.5.0, < 2.5.6"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-61720", "lastModified": "2026-09-18T20:17:18.420", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 6.2, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 2.5, "impactScore": 3.6, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-09-18T20:17:18.420", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/FluidSynth/fluidsynth/commit/096e1ff0d09ddcac83d94923440706f76f94bc44"}, {"source": "security-advisories@github.com", "url": "https://github.com/FluidSynth/fluidsynth/releases/tag/v2.5.6"}, {"source": "security-advisories@github.com", "url": "https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-rmc4-c8hw-455w"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-191"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{}