CVE-2026-64620

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On the server side, when a client selects RDP Standard Security, the encrypted client random is decrypted into a fixed 32-byte buffer. 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{"bugzilla": {"description": "FreeRDP: FreeRDP: Remote code execution or denial of service via heap-based buffer overflow", "id": "2502752", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2502752"}, "csaw": false, "cvss3": {"cvss3_base_score": "8.1", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-120", "details": ["A heap-based buffer overflow in FreeRDP's crypto_rsa_common() allows an unauthenticated remote attacker to trigger a denial of service or potential remote code execution. By sending a crafted ciphertext during RDP Standard Security key establishment, the attacker can force a data write before the size is validated, resulting in memory corruption."], "mitigation": {"lang": "en:us", "value": "To mitigate, explicitly disable legacy RDP Standard Security and enforce Network Level Authentication (NLA/TLS) on the server. Additionally, restrict network access to trusted clients via firewalls, or disable the FreeRDP service entirely if not needed, remembering to restart the service to apply any configuration changes."}, "name": "CVE-2026-64620", "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": "Out of support scope", "package_name": "freerdp", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "freerdp", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "freerdp", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "freerdp", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-07-20T12:04:53Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-64620\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-64620\nhttps://github.com/FreeRDP/FreeRDP/commit/1f7a716d39b5605bb8a83b0c3c97a6ce386609ef\nhttps://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-pjqx-v446-x7fc\nhttps://www.vulncheck.com/advisories/freerdp-before-heap-buffer-overflow-via-crypto-rsa-common"], "statement": "An unauthenticated remote attacker can trigger a heap buffer overflow in FreeRDP by sending a crafted ciphertext during key establishment. \nRed Hat rates this vulnerability as Important rather than Critical due to inherent mitigations in Red Hat environments. Specifically, RHEL's built-in memory defenses (such as glibc heap hardening) reliably reduce the threat of remote code execution down to a localized service crash (Denial of Service). Furthermore, the flaw is only reachable if an administrator explicitly configures the server to use the non-default, legacy \"RDP Standard Security.", "threat_severity": "Important"}

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