Unauthenticated memory disclosure via undersized CS_SECURITY block
Published Jul 20, 2026 · Updated Jul 20, 2026
Out-of-bounds read in xrdp 0.10.6 and earlier allows remote attackers to disclose process memory via a malformed RDP handshake. xrdp_sec_process_mcs_data_CS_SECURITY reads the four-byte encryptionMethods field without first confirming that four bytes remain in the declared CS_SECURITY data block. No authentication or user interaction is required, and the read is limited to a small number of bytes that can expose process memory for use in an exploit chain.
Summary
What happened
Out-of-bounds read in xrdp 0.10.6 and earlier allows remote attackers to disclose process memory via a malformed RDP handshake. xrdp_sec_process_mcs_data_CS_SECURITY reads the four-byte encryptionMethods field without first confirming that four bytes remain in the declared CS_SECURITY data block. No authentication or user interaction is required, and the read is limited to a small number of bytes that can expose process memory for use in an exploit chain.
The record
- CVE
- CVE-2026-55639
- Published
- Jul 20, 2026
- Updated
- Jul 20, 2026
- Vendor
- neutrinolabs
- Product
- xrdp
- Classifications
- CWE-125
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 20, 2026CVE publishedPublication date reported by the CVE source.
- Jul 20, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=< 0.10.6.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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