{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-55194", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-06-16T15:20:43.087Z", "datePublished": "2026-08-19T17:50:30.158Z", "dateUpdated": "2026-08-21T03:55:49.107Z"}, "containers": {"cna": {"title": "FreeRDPHeap-buffer-overflow write in TS Gateway RPC RESPONSE reassembly due to alloc_hint capacity mismatch", "problemTypes": [{"descriptions": [{"cweId": "CWE-122", "lang": "en", "description": "CWE-122: Heap-based Buffer Overflow", "type": "CWE"}]}], "metrics": [{"cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 8.7, "baseSeverity": "HIGH", "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", "version": "4.0"}}], "references": [{"name": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9gxm-3mf5-f5cx", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9gxm-3mf5-f5cx"}, {"name": "https://github.com/FreeRDP/FreeRDP/pull/12873", "tags": ["x_refsource_MISC"], "url": "https://github.com/FreeRDP/FreeRDP/pull/12873"}, {"name": "https://github.com/FreeRDP/FreeRDP/commit/9f2da52c2341cc14a96ad12e69c5b83d0bcd8b5a", "tags": ["x_refsource_MISC"], "url": "https://github.com/FreeRDP/FreeRDP/commit/9f2da52c2341cc14a96ad12e69c5b83d0bcd8b5a"}, {"name": "https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0", "tags": ["x_refsource_MISC"], "url": "https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0"}], "affected": [{"vendor": "FreeRDP", "product": "FreeRDP", "versions": [{"version": "< 3.27.0", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-08-19T17:50:30.158Z"}, "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."}], "source": {"advisory": "GHSA-9gxm-3mf5-f5cx", "discovery": "UNKNOWN"}}, "adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-08-20T00:00:00+00:00", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3", "id": "CVE-2026-55194"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-21T03:55:49.107Z"}}]}}

{}

{"affected": [{"affectedData": [{"product": "FreeRDP", "vendor": "FreeRDP", "versions": [{"status": "affected", "version": "< 3.27.0"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "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."}], "id": "CVE-2026-55194", "lastModified": "2026-08-21T04:18:04.567", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 8.7, "baseSeverity": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "PASSIVE", "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", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-55194", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-08-20T00:00:00+00:00", "version": "2.0.3"}}]}, "published": "2026-08-19T18:16:44.857", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/FreeRDP/FreeRDP/commit/9f2da52c2341cc14a96ad12e69c5b83d0bcd8b5a"}, {"source": "security-advisories@github.com", "url": "https://github.com/FreeRDP/FreeRDP/pull/12873"}, {"source": "security-advisories@github.com", "url": "https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0"}, {"source": "security-advisories@github.com", "url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9gxm-3mf5-f5cx"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-122"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{"bugzilla": {"description": "FreeRDP: FreeRDP: Heap-buffer-overflow allows arbitrary code execution via crafted RPC response", "id": "2519824", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2519824"}, "csaw": false, "cvss3": {"cvss3_base_score": "8.8", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-120", "details": ["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.", "A flaw was found in FreeRDP. A remote attacker, specifically a malicious TS Gateway, can exploit a heap-buffer-overflow vulnerability by sending a specially crafted Remote Desktop Protocol (RDP) response. This occurs because the client incorrectly uses a smaller `alloc_hint` value instead of the actual `StubLength` for buffer capacity during response reassembly. This allows attacker-controlled data to be written beyond the intended buffer, leading to a client crash and potentially enabling arbitrary code execution."], "mitigation": {"lang": "en:us", "value": "To mitigate this vulnerability, avoid connecting through untrusted TS Gateways (RD Gateways) or disable gateway parameters (such as omitting `/g:` in `xfreerdp`) to force direct RDP connections and bypass RPC response parsing."}, "name": "CVE-2026-55194", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "freerdp", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "freerdp", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "freerdp", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "freerdp", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "freerdp", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-19T17:50:30Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-55194\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-55194\nhttps://github.com/FreeRDP/FreeRDP/commit/9f2da52c2341cc14a96ad12e69c5b83d0bcd8b5a\nhttps://github.com/FreeRDP/FreeRDP/pull/12873\nhttps://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0\nhttps://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9gxm-3mf5-f5cx"], "statement": "A heap buffer overflow flaw was found in FreeRDP's TS Gateway RPC client (`libfreerdp/core/gateway/rpc_client.c`). During response fragment reassembly in `rpc_client_recv_fragment`, stream allocation relies on the server-provided `alloc_hint` rather than the actual `StubLength`. A malicious TS Gateway can send a `PTYPE_RESPONSE` packet with a small `alloc_hint` and a larger payload, causing `Stream_Write` to overwrite memory beyond the fixed 4096-byte buffer (`pdu->s`). This can result in client crashes or potential arbitrary code execution.", "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,3.27.0)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "FreeRDP", "source": "cna", "vendor": "FreeRDP"}, "product": "freerdp", "vendor": "freerdp"}], "created": "2026-08-19T19:45:03.959404+00:00", "updated": "2026-08-21T03:00:04.580944+00:00", "vendors": ["freerdp", "freerdp$PRODUCT$freerdp"]}