CVE-2026-61721
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.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H
- Puntuación base: 8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.19%
- Percentil entre todas las CVEs puntuadas: 8
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1068Exploitation for Privilege Escalationprivilege escalation75 % - Impacto principal
T1499.004Application or System Exploitationimpact80 % - Impacto secundario
T1005Data from Local Systemcollection70 % - Impacto secundario
T1040Network Sniffingcredential access · discovery60 %
Archivo DLS malformado ejecuta código sin privilegios (AV:L, PR:N); loop points fuera de rango causan lectura OOB, divulgación de memoria y denegación de servicio durante renderizado de audio.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-122, CWE-125
Referencias
JSON original (NVD)
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"id": "CVE-2026-61721",
"role": "CISA Coordinator",
"options": [
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"version": "2.0.3",
"timestamp": "2026-09-18T20:21:34.730495Z"
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"integrityImpact": "LOW",
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"confidentialityImpact": "HIGH"
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"affected": [
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"source": "security-advisories@github.com",
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"published": "2026-09-18T20:17:18.567",
"references": [
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"url": "https://github.com/FluidSynth/fluidsynth/commit/2354c2a9acdb26de7cdcd37c903ee108f46c0a7d",
"source": "security-advisories@github.com"
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"value": "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."
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"lastModified": "2026-09-23T18:12:04.247",
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