Bug 2502983

Summary: CVE-2026-55238 xrdp: improper input validation in capability negotiation leads to denial of service [fedora-all]
Product: [Fedora] Fedora Reporter: Guilherme de Almeida Suckevicz <gsuckevi>
Component: xrdpAssignee: Bojan Smojver <bojan>
Status: CLOSED ERRATA QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: bojan, mlewissmith, shngmao
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["f26f93f0-3d03-4f2b-9e22-db060b618fdb"]}
Fixed In Version: xrdp-0.10.6.1-3.fc44 xrdp-0.10.6.1-3.fc43 Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2026-07-26 00:58:09 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2502925    

Description Guilherme de Almeida Suckevicz 2026-07-20 19:48:53 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

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.

Comment 1 Fedora Update System 2026-07-21 09:29:50 UTC
FEDORA-2026-952a486b39 (xrdp-0.10.6.1-3.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-952a486b39

Comment 2 Fedora Update System 2026-07-21 09:30:14 UTC
FEDORA-2026-9d3c766833 (xrdp-0.10.6.1-3.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-9d3c766833

Comment 3 Fedora Update System 2026-07-26 00:58:09 UTC
FEDORA-2026-9d3c766833 (xrdp-0.10.6.1-3.fc44) has been pushed to the Fedora 44 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 4 Fedora Update System 2026-07-26 01:16:54 UTC
FEDORA-2026-952a486b39 (xrdp-0.10.6.1-3.fc43) has been pushed to the Fedora 43 stable repository.
If problem still persists, please make note of it in this bug report.