FreeRDP CVE-2026-110829

Exploitation requires the victim to run a FreeRDP client (versions 3.0.0 through 3.31.x) and initiate an RDP session to an attacker-controlled or compromised server, with the rdpsnd (audio redirection) channel negotiated - the malformed PDU must arrive on a fresh channel. The specific trigger is a rdpsnd fragment with CHANNEL_FLAG_LAST set but CHANNEL_FLAG_FIRST absent. Limiting factors: the attacker must occupy the server side of the connection (not an arbitrary remote host), the user must actively connect (UI:P / passive interaction), and the outcome is only a client crash - there is no confidentiality, integrity, or code-execution impact. Clients that never connect to untrusted servers, or deployments on FreeRDP 3.32.0+, are not exposed.

This is a client-side denial-of-service vulnerability with impact strictly limited to availability - the CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H) confirms no confidentiality or integrity impact, only VA:H, consistent with the CWE-476 null pointer dereference and the 'crash the client' description. The 7.1 score reflects the availability-only impact plus the required passive user interaction (UI:P): the attack is network-reachable and needs no authentication (PR:N), but it is a malicious-server-attacks-client model, so a victim must be induced to connect their FreeRDP client to an attacker-controlled or compromised RDP server. No EPSS score, CISA KEV listing, or public POC was provided in the intelligence, so there is no evidence of active exploitation or weaponization - exploitation status is 'no public exploit identified at time of analysis.' The realistic priority is MODERATE-to-LOW: a crash-only bug cannot be used for code execution or data theft, and the server-side-attacker requirement limits mass exploitation; it matters most where FreeRDP clients auto-connect to untrusted gateways/brokers. Note a signal nuance: PR:N technically means unauthenticated, but the practical attacker position is 'operator of the RDP server the victim connects to,' which is a meaningful limiting factor the raw score does not convey.

An attacker stands up or compromises an RDP server and lures a user to connect their FreeRDP-based client (e.g., via a malicious gateway, phishing link, or man-in-the-middle). Once the rdpsnd audio channel is negotiated on a fresh connection, the server sends a malformed rdpsnd PDU fragment with CHANNEL_FLAG_LAST set but not CHANNEL_FLAG_FIRST, triggering a null pointer dereference that crashes the client. No public exploit code was identified in the provided intelligence; impact is limited to a denial of service with no code execution.