RDP Server Vulnerability in xrdp from Neutrinolabs

CVE-2026-55238

What is CVE-2026-55238?

The xrdp open source RDP server has a vulnerability that arises during the capability negotiation phase, specifically with the processing of RDP Confirm Active PDU. The parser lacks adequate length validation for certain capability sets, which could enable a remote, unauthenticated attacker to exploit this flaw by sending a specially crafted RDP packet with malformed capability data. The absence of bounds checks may result in out-of-bounds memory reads, potentially leading to the termination of the xrdp service. While the default behavior of xrdp forks a new process for each connection, making a complete service disruption unlikely, the vulnerability remains a serious concern. Users are advised to upgrade to version 0.10.6.1 or later to mitigate this issue.

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