FKIE_CVE-2026-61720

Vulnerability from fkie_nvd - Published: 2026-09-18 20:17 - Updated: 2026-09-24 21:25
Severity
6.2 (Medium) - CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
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.
References
security-advisories@github.comhttps://github.com/FluidSynth/fluidsynth/commit/096e1ff0d09ddcac83d94923440706f76f94bc44
security-advisories@github.comhttps://github.com/FluidSynth/fluidsynth/releases/tag/v2.5.6
security-advisories@github.comhttps://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-rmc4-c8hw-455w
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "fluidsynth",
          "vendor": "FluidSynth",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2.5.0, \u003c 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": "2026-09-24T21:25:27.050",
  "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"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-61720",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-09-21T16:27:05.665077Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "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": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-191"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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