Buffer over-read in xrdp - CVE-2026-55238
Published: July 1, 2026
Vulnerability identifier: #VU136615
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-55238
CWE-ID: CWE-126
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: neutrinolabs
Affected software:
xrdp
xrdp
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to out-of-bounds read in the RDP Confirm Active PDU capability set parser when processing crafted capability negotiation data. A remote attacker can send a specially crafted RDP packet to cause a denial of service.
By default, xrdp forks a new process for each connection, so exploitation is unlikely to bring down the entire service.
How to mitigate CVE-2026-55238
Install security update from vendor's website.