CVE-2026-55639: xrdp is an open source RDP server

Q: How do I fix CVE-2026-55639?

xrdp: upgrade to 0.10.6.1. Exact commands for each OS are on this page.

Q: Is CVE-2026-55639 being exploited?

CVE-2026-55639 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-55639 affect?

CVE-2026-55639 affects xrdp. Severity is medium (CVSS 5.3). 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.

Q: How urgent is CVE-2026-55639?

Priority 32/100. Remotely exploitable, no login, no user action

Routine

MEDIUM 5.3REMOTEUPGRADE

CVE-2026-55639 is a medium-severity flaw (CVSS 5.3) affecting xrdp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 64%)
CISA exploited list	No
Weakness	CWE-125
Published	2026-07-20
Last modified	2026-10-24

Publisher (CNA): GitHub, Inc. · Vendor: neutrinolabs

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-20 18:16 UTCPublished CVE record published
2026-10-24 20:10 UTCUpdated Record last modified

neutrinolabs xrdp UPGRADE

Affected: < 0.10.6.1

Fixed in: 0.10.6.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy xrdp || rpm -q xrdp || xrdp --version

2. UPGRADE to 0.10.6.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade xrdp

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade xrdp

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-55639?

xrdp: upgrade to 0.10.6.1. Exact commands for each OS are on this page.

Is CVE-2026-55639 being exploited?

CVE-2026-55639 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-55639 affect?

CVE-2026-55639 affects xrdp. Severity is medium (CVSS 5.3). 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.

How urgent is CVE-2026-55639?

Priority 32/100. Remotely exploitable, no login, no user action

Software pages

WinRM and RDP vulnerabilities

Related CVEs

CVE-2026-41252 CRITICAL 9.8 UPGRADE xrdp is an open source RDP server
CVE-2026-41521 HIGH 8.2 UPGRADE xrdp is an open source RDP server
CVE-2026-44178 HIGH 8.8 UPGRADE xrdp is an open source RDP server
CVE-2026-54538 HIGH 7.5 UPGRADE xrdp is an open source RDP server
CVE-2026-55645 MEDIUM 6.5 UPGRADE xrdp is an open source RDP server

References

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