Medium severity · published Jul 20, 2026
CVE-2026-55639
xrdp: Out-of-bounds read in GCC Conference Create Request CS_SECURITY processing (xrdp_sec_process_mcs_data_CS_SECURITY)
5.3
CVSS
0.4%
EPSS
No
On KEV
Description
xrdp is an open source RDP server. Versions 0.10.6 and prior contain a vulnerability concerning the parsing of Client Security Data within the Client MCS Connect Initial PDU with GCC Conference Create Request during the connection sequence. During the initial capability and security negotiation phase, the parser fails to perform sufficient length validation for the incoming data block. A remote, unauthenticated attacker could potentially exploit this flaw by sending a specially crafted RDP packet containing malformed data. Due to missing bounds checks, the xrdp process may read a small number of bytes beyond the declared data block boundary, potentially disclosing process memory contents that could be combined with other vulnerabilities. This issue has been fixed in version 0.10.6.1.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 37% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
XR
xrdp · neutrinolabs
< 0.10.6.1 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-55639
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-55639
Product
https://github.com/neutrinolabs/xrdp/releases/tag/v0.10.6.1
Vendor Advisory
https://github.com/neutrinolabs/xrdp/security/advisories/GHSA-6g36-mxcf-r3gc
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