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A critical heap-based buffer overflow in FreeRDP affects versions through 3.27.1, allowing an unauthenticated attacker to trigger memory corruption before authentication when RDP Standard Security is enabled. The flaw is in crypto_rsa_common() in libfreerdp/crypto/crypto.c, where BN_bn2bin() writes decrypted modular-exponentiation output into a caller-supplied buffer before verifying that the data fits, creating an out-of-bounds heap write condition.
An attacker can exploit the issue by sending a crafted RSA ciphertext for the encrypted client random during the RDP handshake. Because the server exposes its RSA public key, the ciphertext can be made to decrypt to data as large as the RSA modulus length—such as 256 bytes with RSA-2048—while the target buffer is only 32 bytes, producing roughly 224 bytes of attacker-controlled overflow and causing denial of service. The vulnerability is tracked as CVE-2026-64620, carries a CVSS v3.1 score of 9.8, and is fixed in FreeRDP 3.28.0.
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A critical heap-based buffer overflow in FreeRDP's crypto_rsa_common() affects versions up to 3.27.1 and is fixed in FreeRDP 3.28.0. The flaw allows a pre-authentication attacker using RDP Standard Security to trigger an out-of-bounds heap write and denial of service.
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A high-severity double-free vulnerability tracked as **`CVE-2026-64621`** was disclosed in **FreeRDP** versions **3.x through 3.27.1**, affecting the parsing of the `selectedmonitors` field in `.rdp` connection files. The flaw is located in `freerdp_client_rdp_file_apply_to_settings()` in `client/common/file.c`, where an error path can free a non-owning pointer and leave `settings->MonitorIds` dangling, leading to a second free during teardown. The issue is classified as **CWE-415** and can affect FreeRDP CLI clients including **`xfreerdp`**, **`sdl-freerdp`**, and **`wlfreerdp`** in their default configurations. Attackers could exploit the bug by persuading a user to open a crafted `.rdp` file containing oversized monitor tokens, resulting in a size-controlled double-free with potential impacts to **integrity** and **availability**, and limited **confidentiality** exposure under the published CVSS assessment. The vulnerability has been fixed in **FreeRDP 3.28.0**, and public references include a GitHub security advisory, a fixing commit in the FreeRDP repository, and a VulnCheck advisory.
Jul 20, 2026
Kaspersky disclosed **CVE-2025-68670**, a pre-authentication remote code execution flaw in the open-source **xrdp** server, after finding the issue during a security audit of Kaspersky USB Redirector. The vulnerability stems from improper handling of the RDP domain field: xrdp converts client-supplied UTF-16 data to UTF-8 and then copies attacker-controlled domain input into a **256-byte stack buffer** without sufficient bounds checking, creating a stack-based buffer overflow that can be triggered before authentication. Kaspersky said it reported the bug to the xrdp maintainers in December 2025, and the project has since released fixes in **xrdp 0.10.5** and backported patches to **0.9.27** and **0.10.4.1**, alongside a security bulletin. The disclosure notes that while stack canaries may complicate straightforward exploitation, they are not a complete mitigation, and organizations running exposed or internally reachable xrdp services should prioritize upgrading to patched versions.
Jun 29, 2026
Microsoft released fixes for two **Windows Remote Desktop Protocol (RDP)** information disclosure vulnerabilities, `CVE-2026-42908` and `CVE-2026-45639`, that allow a remote, unauthenticated attacker to trigger out-of-bounds reads and expose sensitive memory without user interaction. According to reporting on the June 9, 2026 security updates, `CVE-2026-42908` can disclose local memory addresses and weaken **ASLR**, while `CVE-2026-45639` can reveal process memory including credentials, session tokens, and protocol state data. Microsoft rated both flaws **Important** with **CVSS 7.5** and said exploitation was considered less likely at release, with no public exploits reported. The vulnerabilities affect a broad set of Windows platforms, including **Windows 10**, **Windows 11**, **Windows Server 2012 through 2025**, and Microsoft’s Remote Desktop client offerings for Windows desktop. The disclosures arrive amid continued scrutiny of the RDP ecosystem after earlier reports of severe Remote Desktop weaknesses, including `CVE-2025-29967` in **RD Gateway** and `CVE-2025-29966` and `CVE-2025-48817` in the **Windows Remote Desktop Client**, which were described as enabling remote code execution through heap overflow or path traversal conditions. Organizations were urged to prioritize patching internet-exposed RDP systems and strengthen access controls with VPNs, bastion hosts, strong authentication, and monitoring.
Jun 29, 2026