Cyber Resilience

CVE-2026-55626

Auth Bypass in Neutrinolabs Xrdp 0.10.3 – 0.10.6.1

Published
20 July 2026
Modified
28 July 2026
Patch / advisory
CVSS Score v3.1 8.0
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
EPSS Score 0.0013 3th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-55626 is a high-severity Improper Authentication (CWE-287) vulnerability in Neutrinolabs Xrdp. Its CVSS base score is 8.0 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique RDP Hijacking (T1563.002); ranked at the 3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and SC-39 (Process Isolation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

xrdp is an open source RDP server. In versions 0.10.6 and prior, when an authenticated user session is initialized using the Xvnc backend over UNIX domain sockets, the Xvnc process is launched with insufficient authentication mechanisms. A local authenticated attacker…

more

could exploit this vulnerability to bypass intended session isolation, allowing them to unauthorizedly view or control the active desktop sessions of other users on the same system. Users using other backends, such as xorgxrdp or Xvnc over TCP sockets, are not affected. This issue has been fixed in version 0.10.6.1.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1563.002 RDP Hijacking Lateral Movement
Adversaries may hijack a legitimate user’s remote desktop session to move laterally within an environment.
Why these techniques?

Vulnerability in xrdp Xvnc backend directly enables unauthorized access to and control of other users' active RDP sessions by bypassing session isolation (RDP session hijacking).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-35512Same product: Neutrinolabs Xrdp
CVE-2026-54538Same product: Neutrinolabs Xrdp
CVE-2026-44978Same product: Neutrinolabs Xrdp
CVE-2026-41521Same product: Neutrinolabs Xrdp
CVE-2023-40184Same product: Neutrinolabs Xrdp
CVE-2026-42218Same product: Neutrinolabs Xrdp
CVE-2026-33516Same product: Neutrinolabs Xrdp
CVE-2026-32107Same product: Neutrinolabs Xrdp
CVE-2026-33689Same product: Neutrinolabs Xrdp
CVE-2026-41252Same product: Neutrinolabs Xrdp

Affected Assets

neutrinolabs
xrdp
0.10.3 — 0.10.6.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-3 Access Enforcement
  • SC-39 Process Isolation
  • AC-6 Least Privilege
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 14 hardening rules · 5 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.4.4
  • V6.5.4
  • V6.5.5
  • V6.5.7

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly enforces access control between user sessions so that an authenticated local user cannot view or control another user's Xvnc desktop session.

prevent

Requires process isolation so that the Xvnc backend launched over UNIX domain sockets cannot bypass intended session boundaries and access other users' desktops.

prevent

Limits privileges of the Xvnc process so that even if launched with weak authentication it cannot reach or manipulate other users' active sessions.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-03 full match
prevents

Directly requires authentication of users/services/hardware, which eliminates missing authentication for critical functions.

PR.AA-04 mostly match
prevents

PR.AA-04 directly enables verification of identity assertions (mostly preventing CWE-287 in that scope) yet leaves many other authentication failure modes unaddressed (only partial prevention overall).

PR.AA-01 partial match
prevents

PR.AA-01 supplies and governs credentials/tokens that authentication relies on, removing some weak-credential cases, yet leaves verification logic, missing checks, and protocol flaws untouched.

PR.AA-02 partial match
prevents

PR.AA-02 ensures valid enrollment and unique credential binding, which reduces some improper-auth risks at issuance time but leaves runtime claim verification untouched, so each direction only partially addresses the other.

PR.AA-05 partial match
prevents

Defining and enforcing authorizations assumes prior authentication and therefore only partially mitigates the absence of authentication.

PR.IR-01 partial match
prevents

Protecting networks from unauthorized access can be undermined by missing authentication but does not address the root authentication gap.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Requiring authentication methods whose strength matches the sensitivity of the data and mandating multi-factor authentication directly blocks attempts to access resources without proving identity.

prevents

Verifying user identity before issuing replacement credentials and forcing changes after compromise reduces the likelihood that authentication bypass can be achieved through stolen or weak credentials.

prevents

Mandating segregated approval and oversight for non-human identities reduces the chance that weak or orphaned credentials can be exploited for unauthorized authentication.

prevents

Mandating authentication requirements for critical functions at the requirements-gathering stage ensures that essential operations are not left unprotected by missing login or verification mechanisms.

mitigates

Requiring authentication mechanisms and technical parameters for secure connections ensures that network services verify user identity before granting access, preventing exploitation of missing or weak authentication.

prevents

Security requirements specified early and verified through testing drive the consistent implementation of authentication mechanisms, decreasing the likelihood that authentication steps are omitted or incorrectly applied.

References