CVE-2026-55564

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{"affected": [{"affectedData": [{"product": "FreeRDP", "vendor": "FreeRDP", "versions": [{"status": "affected", "version": "< 3.27.0"}]}], "source": "security-advisories@github.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*", "matchCriteriaId": "F9603C86-160B-40E9-BA5D-813AA03B1A44", "versionEndExcluding": "3.27.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, the glyph_cache_get function in libfreerdp/cache/glyph.c checks whether index is greater than cache->number instead of greater than or equal to it. A malicious RDP server can use GLYPH_FRAGMENT_USE replay in update_process_glyph_fragments to make the default cache receive index 254 when cache->number is 254, reading one pointer beyond the entries array and dereferencing it as a glyph. This can crash the client and may disclose adjacent heap data. 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 3.27.0, la funci\u00f3n glyph_cache_get en libfreerdp/cache/glyph.c verifica si el \u00edndice es mayor que cache -> number en lugar de mayor o igual que \u00e9l. Un servidor RDP malicioso puede usar la repetici\u00f3n de GLYPH_FRAGMENT_USE en update_process_glyph_fragments para hacer que la cach\u00e9 predeterminada reciba el \u00edndice 254 cuando cache -> number es 254, leyendo un puntero m\u00e1s all\u00e1 del array de entradas y desreferenci\u00e1ndolo como un glifo. Esto puede bloquear al cliente y puede divulgar datos adyacentes del heap. Este problema est\u00e1 solucionado en la versi\u00f3n 3.27.0."}], "id": "CVE-2026-55564", "lastModified": "2026-10-26T11:10:00.157", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 5.4, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 2.5, "source": "security-advisories@github.com", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.1, "baseSeverity": "HIGH", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 4.2, "source": "nvd@nist.gov", "type": "Primary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-55564", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-08-25T03:33:25.244841Z", "version": "2.0.3"}}]}, "published": "2026-08-19T18:16:45.003", "references": [{"source": "security-advisories@github.com", "tags": ["Patch"], "url": "https://github.com/FreeRDP/FreeRDP/commit/c29324750e3cbcba8761f147b7a5235cc686930f"}, {"source": "security-advisories@github.com", "tags": ["Issue Tracking", "Patch"], "url": "https://github.com/FreeRDP/FreeRDP/pull/12885"}, {"source": "security-advisories@github.com", "tags": ["Release Notes"], "url": "https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0"}, {"source": "security-advisories@github.com", "tags": ["Exploit", "Mitigation", "Vendor Advisory"], "url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-6xmj-pr98-cx4c"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Mitigation", "Vendor Advisory"], "url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-6xmj-pr98-cx4c"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-125"}, {"lang": "en", "value": "CWE-193"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{"bugzilla": {"description": "FreeRDP: FreeRDP: Out-of-bounds read in glyph cache leads to denial of service and information disclosure", "id": "2519813", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2519813"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.4", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L", "status": "draft"}, "cwe": "CWE-125", "details": ["FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, the glyph_cache_get function in libfreerdp/cache/glyph.c checks whether index is greater than cache->number instead of greater than or equal to it. A malicious RDP server can use GLYPH_FRAGMENT_USE replay in update_process_glyph_fragments to make the default cache receive index 254 when cache->number is 254, reading one pointer beyond the entries array and dereferencing it as a glyph. This can crash the client and may disclose adjacent heap data. This issue is fixed in version 3.27.0.", "A flaw was found in FreeRDP. A malicious Remote Desktop Protocol (RDP) server can exploit an out-of-bounds read vulnerability in the glyph_cache_get function. By sending crafted glyph fragments, the server can cause the client to read beyond the intended memory buffer. This can lead to a client crash, resulting in a Denial of Service (DoS), and potentially disclose sensitive adjacent heap data."], "mitigation": {"lang": "en:us", "value": "Restrict FreeRDP client connections to trusted Remote Desktop Protocol (RDP) servers only. Avoid connecting to untrusted or potentially malicious RDP servers to prevent exploitation of this client-side vulnerability. If FreeRDP client functionality is not essential, consider removing the `freerdp` package and its dependencies."}, "name": "CVE-2026-55564", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "freerdp", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "freerdp", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "freerdp", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "freerdp", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "freerdp", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-19T17:45:47Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-55564\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-55564\nhttps://github.com/FreeRDP/FreeRDP/commit/c29324750e3cbcba8761f147b7a5235cc686930f\nhttps://github.com/FreeRDP/FreeRDP/pull/12885\nhttps://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0\nhttps://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-6xmj-pr98-cx4c"], "threat_severity": "Moderate"}

{"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": "2026-08-19T19:45:03.959859+00:00", "updated": "2026-08-20T13:15:03.505456+00:00", "vendors": ["freerdp", "freerdp$PRODUCT$freerdp"]}