CVE-2026-55194

{"id": "CVE-2026-55194", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-55194", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-08-21T03:55:49.884406Z"}}], "cvssMetricV31": [{"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}], "cvssMetricV40": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 8.7, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "PASSIVE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "FreeRDP", "product": "FreeRDP", "versions": [{"status": "affected", "version": "< 3.27.0"}]}]}], "published": "2026-08-19T18:16:44.857", "references": [{"url": "https://github.com/FreeRDP/FreeRDP/commit/9f2da52c2341cc14a96ad12e69c5b83d0bcd8b5a", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/FreeRDP/FreeRDP/pull/12873", "tags": ["Issue Tracking", "Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0", "tags": ["Release Notes"], "source": "security-advisories@github.com"}, {"url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9gxm-3mf5-f5cx", "tags": ["Exploit", "Mitigation", "Vendor Advisory"], "source": "security-advisories@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-122"}]}], "descriptions": [{"lang": "en", "value": "FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, rpc_client_recv_fragment in libfreerdp/core/gateway/rpc_client.c ensures the response reassembly stream capacity using only the server-declared alloc_hint rather than the actual StubLength about to be written. A malicious TS Gateway can send a PTYPE_RESPONSE with a small alloc_hint and a much larger frag_length, causing Stream_Write to copy attacker-controlled stub data beyond the 4096-byte pdu->s buffer. This can crash the client and may permit code execution through heap corruption. This issue is fixed in version 3.27.0."}, {"lang": "es", "value": "FreeRDP es una implementaci\u00f3n gratuita del Protocolo de Escritorio Remoto. Antes de la versi\u00f3n 3.27.0, rpc_client_recv_fragment en libfreerdp/core/gateway/rpc_client.c asegura la capacidad del flujo de reensamblaje de la respuesta utilizando solo el alloc_hint declarado por el servidor en lugar del StubLength real que est\u00e1 a punto de escribirse. Una puerta de enlace TS maliciosa puede enviar un PTYPE_RESPONSE con un alloc_hint peque\u00f1o y un frag_length mucho mayor, haciendo que Stream_Write copie datos stub controlados por el atacante m\u00e1s all\u00e1 del b\u00fafer pdu -> s de 4096 bytes. Esto puede bloquear al cliente y puede permitir la ejecuci\u00f3n de c\u00f3digo a trav\u00e9s de la corrupci\u00f3n de la pila. Este problema se solucion\u00f3 en la versi\u00f3n 3.27.0."}], "lastModified": "2026-10-26T11:10:00.157", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F9603C86-160B-40E9-BA5D-813AA03B1A44", "versionEndExcluding": "3.27.0"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}