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Fencer Vulns
medium 5.3

CVE-2026-55238 json

xrdp: Malformed Confirm Active capability sets cause out-of-bounds reads

published 2026-07-20 3 mo ago modified 2026-10-24 15 d ago also EUVD-2026-46036

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 44%
public exploits
0
none known

Summary

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.

Patch / fix

  • neutrinolabs xrdp 0.10.6.1
  • xrdp Debian 12 0.9.21.1-1+deb12u3
  • xrdp Debian 13 0.10.1-3.1+deb13u2
  • xrdp Debian 14 0.10.6.1-2

debian advisories DEBIAN-CVE-2026-55238

  • xrdp openSUSE Tumbleweed 0.10.6.1-1.1

opensuse advisories openSUSE-SU-2026:11543-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-55238 updated cvss 5.3

xrdp: improper input validation in capability negotiation leads to denial of service

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
3 mo ago

Exploit prediction

0.52% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected products

  • neutrinolabs xrdp

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.