Remote Desktop Client CVE-2026-47289

Exploitation requires the victim to initiate an RDP session from a vulnerable Remote Desktop Client to an attacker-controlled or compromised RDP server (UI:R in the CVSS vector); the attacker does not need any prior credentials on the victim machine (PR:N) and the network vector (AV:N) is satisfied as soon as the client establishes the outbound RDP connection. Limiting factors are the requirement for user-initiated connection (no zero-click path indicated), the need for outbound RDP egress to reach the malicious server (commonly blocked or proxied in enterprise networks), and execution in the context of the connecting user rather than SYSTEM - so least-privilege user accounts constrain blast radius. Specific Windows builds and client versions must be confirmed from the MSRC advisory before scoping vulnerable estate.

The CVSS 3.1 vector AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H indicates network-reachable, low-complexity exploitation with no prior authentication but requiring user interaction, yielding high impact across confidentiality, integrity, and availability - a base score of 8.8. EPSS, KEV status, and SSVC data are not provided in the input, so probability of exploitation and active-exploitation signals cannot be quantified from this dataset. Importantly, the AV:N rating is somewhat counter-intuitive for a client-side bug: exploitation in practice requires the victim to initiate (or be lured into) an RDP connection to a malicious or compromised server, which is reflected in UI:R. There is no public exploit identified at time of analysis, and the single available reference (the MSRC advisory) is the authoritative source - independent corroboration from NVD enrichment, vendor patch metadata, or third-party telemetry is not present in the provided data.

An attacker stands up a malicious RDP server and lures a target - via a phishing email containing a crafted .rdp file, a malicious link, or a compromised internal jump host - into initiating an outbound RDP connection. During the protocol handshake or subsequent channel negotiation, the server returns malformed structures that overflow a heap buffer in the client, leading to code execution in the user's session, after which the attacker can steal credentials, pivot internally, or stage further payloads. No public exploit has been identified at time of analysis, but the low attack complexity makes weaponization plausible once technical details circulate.