CVE-2026-54538

Published Jul 20, 2026

Last updated a day ago

CVSS high 7.5

Overview

Description
xrdp is an open source RDP server. In versions 0.10.6 and prior, a n issue was discovered where the software fails to properly validate the totalLength field within the RDP protocol control header during packet reception. An unauthenticated remote attacker can exploit this vulnerability by sending a specially crafted packet that forces the xrdp process or thread into an infinite, CPU-bound loop. Because the internal pointer fails to advance and the deadlock prevention mechanism is bypassed for specific protocol data unit types, the process consumes excessive CPU resources indefinitely. This can render the xrdp service unavailable and potentially lead to system-wide resource exhaustion if multiple malicious connections are established. This issue has been fixed in version 0.10.6.1.
Source
security-advisories@github.com
NVD status
Analyzed
Products
xrdp

Risk scores

CVSS 3.1

Type
Secondary
Base score
7.5
Impact score
3.6
Exploitability score
3.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity
HIGH

Weaknesses

security-advisories@github.com
CWE-835

Social media

Hype score
Not currently trending

Configurations

Related CVEs

  1. xrdp is an open source RDP server. Versions 0.10.6 and prior contain a vulnerability concerning the processing of Client Control PDUs. During the RDP connection sequence, the parser does not perform sufficient length validation before reading specific data fields from the network stream. A remote, unauthenticated attacker could potentially exploit this flaw by sending a specially crafted, truncated Client Control PDU. Due to missing bounds checks, the xrdp process may perform out-of-bounds memory reads, which can result in the termination of the service (Denial of Service). However, since xrdp forks a new process for each connection by default, an out-of-bounds read causing a process crash is unlikely to bring down the entire xrdp service.This issue has been fixed in version 0.10.6.1.•CVE-2026-55645
  2. xrdp is an open source RDP server. Versions 0.10.6 and prior contain a vulnerability concerning the processing of RDP Confirm Active PDU, where during the capability negotiation phase, the parser did not perform sufficient length validation for specific capability sets. A remote, unauthenticated attacker could potentially exploit this flaw by sending a specially crafted RDP packet containing malformed capability data. Due to missing bounds checks, the xrdp process may perform out-of-bounds memory reads, which can result in the termination of the service (Denial of Service). However, since xrdp forks a new process for each connection by default, an out-of-bounds read causing a process crash is unlikely to bring down the entire xrdp service. This issue has been fixed in version 0.10.6.1.•CVE-2026-55238
  3. xrdp is an open source RDP server. Versions 0.10.6 and prior contain a heap out-of-bounds read vulnerability within the FIPS-specific receive paths. This vulnerability does not affect the default configuration of xrdp. The vulnerability is only exploitable when the security layer is set to security_layer=negotiate or security_layer=rdp, and the crypto level is changed to crypt_level=fips in xrdp.ini. In this specific non-default mode, the server fails to validate the FIPS padding length field, leading to a pointer underflow and a subsequent negative length calculation. An unauthenticated remote attacker can exploit this by sending a crafted FIPS-protected PDU, causing a heap out-of-bounds read that results in a process crash and denial of service (DoS). However, since xrdp forks a new process for each connection by default, an out-of-bounds read causing a process crash is unlikely to bring down the entire xrdp service. This issue has been fixed in version 0.10.6.1.•CVE-2026-44978
  4. xrdp is an open source RDP server. Versions 0.10.6 and prior contain a heap-based buffer overflow vulnerability within the virtual channel forwarding mechanism. When forwarding data from a remote client to the internal channel server, the xrdp process utilizes a fixed-size buffer without adequate bounds checking on the incoming payload. An authenticated remote attacker can exploit this flaw by sending a specially crafted virtual channel message that exceeds the buffer capacity, leading to heap memory corruption. This may result in a denial of service or the execution of arbitrary code with the privileges of the xrdp process. This issue has been fixed in version 0.10.6.1.•CVE-2026-44178
  5. xrdp is an open source RDP server. Versions 0.10.6 and prior contain a timing side-channel vulnerability in the login interface. Due to a discrepancy in response processing times, a remote attacker can infer the existence of a username on the system, leading to unauthorized information disclosure via username enumeration. This issue has been fixed in version 0.10.6.1.•CVE-2026-42218

References

Sources include official advisories and independent security research.