CVE-2026-55238
xrdp: Malformed Confirm Active capability sets cause out-of-bounds reads
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
5.3
xrdp: Malformed Confirm Active capability sets cause out-of-bounds reads
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.
- Record
CVE-2026-55238- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-126
- Updated
- 2026-11-02
EUVDEUVD-2026-46036
5.3
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.
- Record
EUVD-2026-46036- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
NVD
5.3
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.
- Record
CVE-2026-55238- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-126
- Updated
- 2026-11-02
OSV
5.3
xrdp: Malformed Confirm Active capability sets cause out-of-bounds reads
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.
- Record
CVE-2026-55238- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-126
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-55238
5.3
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.
- Record
DEBIAN-CVE-2026-55238- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-55238
5.3
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.
- Record
UBUNTU-CVE-2026-55238- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
OSVMGASA-2026-0566 No score
Updated xrdp package fixes security vulnerabilities
lib_palette_update Heap Buffer Overflow & RCE. (CVE-2026-41252) lib_framebuffer_update Has Integer Overflow Heap Info Leak & ASLR Bypass. (CVE-2026-41521) Channel Data Forwarding Fixed-Size Buffer Overflow. (CVE-2026-44178) XRDP is vulnerable to a server timing attack, leading to user enumeration. (CVE-2026-42218) Unchecked FIPS padding length in standard RDP Security causes heap out-of-bounds read in HMAC verification. (CVE-2026-44978) Pre-auth infinite loop via totalLength=0 in TS_SHARECONTROLHEADER. (CVE-2026-54538) Malformed Confirm Active capability sets cause out-of-bounds reads. (CVE-2026-55238) No authentication required with Xvnc backend. (CVE-2026-55626) Out-of-bounds read in GCC Conference Create Request CS_SECURITY processing (xrdp_sec_process_mcs_data_CS_SECURITY). (CVE-2026-55639) Out-of-bounds read in Client Control PDU processing (xrdp_rdp_process_data_control). (CVE-2026-55645)
- Record
MGASA-2026-0566- Updated
- 2026-11-02
OSVopenSUSE-SU-2026:11543-1 No score
xrdp-0.10.6.1-1.1 on GA media
These are all security issues fixed in the xrdp-0.10.6.1-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:11543-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
xrdpDebian:12 |
before 0.9.21.1-1+deb12u3, plus listed versions 0.9.21.1-10.9.21.1-1+deb12u10.9.21.1-1+deb12u2 |
0.9.21.1-1+deb12u3 |
xrdpDebian:13 |
before 0.10.1-3.1+deb13u2, plus listed versions 0.10.1-3.10.10.1-3.1+deb13u1 |
0.10.1-3.1+deb13u2 |
xrdpDebian:14 |
before 0.10.6.1-2, plus listed versions 0.10.1-3.10.10.1-40.10.1-4.10.10.2-10.10.2-2 Show 14 moreShow less0.10.4.1-10.10.4.1-20.10.5-10.10.5-20.10.5-30.10.5-40.10.5-50.10.6-10.10.6-20.10.6-30.10.6-40.10.6-50.10.6.1-10.10.6.1-2~bpo13+1 |
0.10.6.1-2 |
xrdpMageia:10 From an advisory covering 10 CVEs |
before 0.10.6.1-2.mga10 | 0.10.6.1-2.mga10 |
xrdpUbuntu:Pro:14.04:LTS |
All versions, plus listed versions 0.6.0-10.6.0-1ubuntu0.10.6.0-1ubuntu0.1+esm10.6.0-1ubuntu0.1+esm20.6.0-1ubuntu0.1+esm3 |
None known |
xrdpUbuntu:Pro:16.04:LTS |
All versions, plus listed versions 0.6.1-20.6.1-2ubuntu0.10.6.1-2ubuntu0.30.6.1-2ubuntu0.3+esm10.6.1-2ubuntu0.3+esm20.6.1-2ubuntu0.3+esm3 |
None known |
xrdpUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 0.9.1-90.9.4-10.9.4-20.9.4-30.9.4-4 Show 7 moreShow less0.9.4-50.9.5-10.9.5-1build10.9.5-20.9.5-2ubuntu0.1~esm10.9.5-2ubuntu0.1~esm20.9.5-2ubuntu0.1~esm3 |
None known |
xrdpUbuntu:Pro:20.04:LTS |
All versions, plus listed versions 0.9.9-10.9.12-10.9.12-1ubuntu0.10.9.12-1ubuntu0.1+esm10.9.12-1ubuntu0.1+esm2 |
None known |
xrdpUbuntu:22.04:LTS |
All versions, plus listed versions 0.9.15-1ubuntu10.9.17-10.9.17-20.9.17-2ubuntu10.9.17-2ubuntu2 Show 5 moreShow less0.9.17-2ubuntu2+esm10.9.17-2ubuntu30.9.17-2ubuntu3+esm10.9.17-2ubuntu3+esm20.9.17-2ubuntu3.1 |
None known |
xrdpUbuntu:24.04:LTS |
All versions, plus listed versions 0.9.21.1-10.9.24-20.9.24-30.9.24-3build10.9.24-3build20.9.24-40.9.24-4ubuntu0.1~esm10.9.24-4ubuntu0.1 |
None known |
Show 4 moreShow less
| Package | Affected | Fixed |
|---|---|---|
xrdpUbuntu:25.10 |
All versions, plus listed versions 0.10.1-30.10.1-3.10.10.1-3.1+deb13u1build0.25.10.1 |
None known |
xrdpUbuntu:26.10 |
All versions, plus listed versions 0.10.1-4.10.10.6.1-2ubuntu1 |
None known |
xrdpUbuntu:26.04:LTS |
All versions, plus listed versions 0.10.1-3.10.10.1-40.10.1-4.10.10.1-4.1ubuntu0.1 |
None known |
xrdpopenSUSE:Tumbleweed From an advisory covering 10 CVEs |
before 0.10.6.1-1.1 | 0.10.6.1-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-55238 is a medium vulnerability (CVSS 5.3) in Neutrinolabs Xrdp, published July 20, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.52%, the 44th percentile. Fixed in xrdp 0.9.21.1-1+deb12u3.
References
github.com/neutrinolabs/xrdp/security/advisories/GHSA-mg8j-x9rw-9xv3
github.com/neutrinolabs/xrdp/releases/tag/v0.10.6.1
github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55238.json
nvd.nist.gov/vuln/detail/CVE-2026-55238
security-tracker.debian.org/tracker/CVE-2026-55238
advisories.mageia.org/MGASA-2026-0566.html
Show 16 moreShow less
bugs.mageia.org/show_bug.cgi?id=35945
lists.fedoraproject.org/archives/list/[email protected]/message/5ZQ6QE47Z3SMILAAOHQ2RKDQFJOK2M4X
lists.fedoraproject.org/archives/list/[email protected]/message/JWYOEVBA3574FXNPXKDS3FPNCQ3SDAOM
lists.debian.org/debian-security-announce/2026/msg00380.html
ubuntu.com/security/CVE-2026-55238
cve.org/CVERecord?id=CVE-2026-55238
suse.com/security/cve/CVE-2026-41252
suse.com/security/cve/CVE-2026-41521
suse.com/security/cve/CVE-2026-42218
suse.com/security/cve/CVE-2026-44178
suse.com/security/cve/CVE-2026-44978
suse.com/security/cve/CVE-2026-54538
suse.com/security/cve/CVE-2026-55238
suse.com/security/cve/CVE-2026-55626
suse.com/security/cve/CVE-2026-55639
suse.com/security/cve/CVE-2026-55645