CVE-2026-61723

FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From 2.5.0 until 2.5.6, the native DLS parser validates ptbl chunks with the unsigned expression cues * 4 + cbsize without checking whether the multiplication and addition fit in 32 bits. A crafted DLS file can supply a large cues value that wraps the expression and passes the chunk-size check, causing poolcues.resize(cues) to request approximately four gigabytes and the parser to read billions of entries beyond the chunk boundary. The excessive allocation and invalid reads can cause denial of service. Builds with enable-native-dls set to OFF are not exposed. This issue is fixed in version 2.5.6.

Database specific

{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-190"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61723.json"
}

References

Affected packages

Git / github.com/fluidsynth/fluidsynth

Affected ranges

Type

GIT

Repo

https://github.com/fluidsynth/fluidsynth

Events

Introduced

df432e151dcaf463b1ecc7e873803bfa19733fd3

Fixed

e5b11058a619246cea42976dacb76ca54be3d45d

Database specific

Show details

{
    "extracted_events": [
        {
            "introduced": "2.5.0"
        },
        {
            "fixed": "2.5.6"
        }
    ],
    "source": "AFFECTED_FIELD"
}

Affected versions

v2.*

v2.5.0

v2.5.1

v2.5.2

v2.5.3

v2.5.4

v2.5.5

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-61723.json"

vanir_signatures

[
    {
        "deprecated": false,
        "digest": {
            "line_hashes": [
                "65741976735742723877597808461499147360",
                "158873129713208397340236107564649355567",
                "27858880504209789441457038429492907366",
                "242142550883552540884961556422285883183"
            ],
            "threshold": 0.9
        },
        "id": "CVE-2026-61723-ae4f73c0",
        "signature_type": "Line",
        "signature_version": "v1",
        "source": "https://github.com/fluidsynth/fluidsynth/commit/e5b11058a619246cea42976dacb76ca54be3d45d",
        "target": {
            "file": "src/sfloader/fluid_dls.cpp"
        }
    },
    {
        "deprecated": false,
        "digest": {
            "function_hash": "109398306651516327573478367773148522902",
            "length": 9029
        },
        "id": "CVE-2026-61723-b1a5b579",
        "signature_type": "Function",
        "signature_version": "v1",
        "source": "https://github.com/fluidsynth/fluidsynth/commit/e5b11058a619246cea42976dacb76ca54be3d45d",
        "target": {
            "file": "src/sfloader/fluid_dls.cpp",
            "function": "fluid_dls_font::fluid_dls_font"
        }
    }
]

vanir_signatures_modified

"2026-09-19T14:14:41Z"