CVE-2026-31883

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, a size_t underflow in the IMA-ADPCM and MS-ADPCM audio decoders leads to heap-buffer-overflow write via the RDPSND audio channel. In libfreerdp/codec/dsp.c, the IMA-ADPCM and MS-ADPCM decoders subtract block header sizes from a size_t variable without checking for underflow. When nBlockAlign (received from the server) is set such that size % block_size == 0 triggers the header parsing at a point where size is smaller than the header (4 or 8 bytes), the subtraction wraps size to ~SIZE_MAX. The while (size > 0) loop then continues for an astronomical number of iterations. This vulnerability is fixed in 3.24.0.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 2.5

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/FreeRDP/FreeRDP/commit/16df2300e1e3f5a51f68fb1626429e58b531b7c8	Patch
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-85x9-4xxp-xhm5	Exploit Patch Vendor Advisory
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-85x9-4xxp-xhm5	Exploit Patch Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-03-13 19:54

Updated : 2026-03-17 14:26

NVD link : CVE-2026-31883

Mitre link : CVE-2026-31883

CVE.ORG link : CVE-2026-31883

JSON object : View

Products Affected

freerdp

freerdp

CWE

CWE-122

Heap-based Buffer Overflow

CWE-191

Integer Underflow (Wrap or Wraparound)

{"id": "CVE-2026-31883", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 6.5, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}, "impactScore": 2.5, "exploitabilityScore": 3.9}, {"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.8, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 3.9}]}, "published": "2026-03-13T19:54:37.190", "references": [{"url": "https://github.com/FreeRDP/FreeRDP/commit/16df2300e1e3f5a51f68fb1626429e58b531b7c8", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-85x9-4xxp-xhm5", "tags": ["Exploit", "Patch", "Vendor Advisory"], "source": "security-advisories@github.com"}, {"url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-85x9-4xxp-xhm5", "tags": ["Exploit", "Patch", "Vendor Advisory"], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-122"}, {"lang": "en", "value": "CWE-191"}]}], "descriptions": [{"lang": "en", "value": "FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, a size_t underflow in the IMA-ADPCM and MS-ADPCM audio decoders leads to heap-buffer-overflow write via the RDPSND audio channel. In libfreerdp/codec/dsp.c, the IMA-ADPCM and MS-ADPCM decoders subtract block header sizes from a size_t variable without checking for underflow. When nBlockAlign (received from the server) is set such that size % block_size == 0 triggers the header parsing at a point where size is smaller than the header (4 or 8 bytes), the subtraction wraps size to ~SIZE_MAX. The while (size > 0) loop then continues for an astronomical number of iterations. This vulnerability is fixed in 3.24.0."}, {"lang": "es", "value": "FreeRDP es una implementaci\u00f3n gratuita del Protocolo de Escritorio Remoto. Anterior a la 3.24.0, un subdesbordamiento de size_t en los decodificadores de audio IMA-ADPCM y MS-ADPCM conduce a una escritura de desbordamiento de b\u00fafer de pila a trav\u00e9s del canal de audio RDPSND. En libfreerdp/codec/dsp.c, los decodificadores IMA-ADPCM y MS-ADPCM restan tama\u00f1os de encabezado de bloque de una variable size_t sin comprobar si hay subdesbordamiento. Cuando nBlockAlign (recibido del servidor) se establece de tal manera que size % block_size == 0 activa el an\u00e1lisis del encabezado en un punto donde size es menor que el encabezado (4 u 8 bytes), la resta envuelve size a ~SIZE_MAX. El bucle while (size > 0) entonces contin\u00faa por un n\u00famero astron\u00f3mico de iteraciones. Esta vulnerabilidad se corrige en la 3.24.0."}], "lastModified": "2026-03-17T14:26:13.760", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "97FCA262-35C3-4B6B-A321-15CE780FCA20", "versionEndExcluding": "3.24.0"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}