# CVE-2026-55626: xrdp: No authentication required with Xvnc backend on RHEL 9

> A local authenticated attacker can bypass session isolation in xrdp with Xvnc backend to view or control other users' desktop sessions.

- **Severity:** High 8.0 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 20 Jul 2026
- **Updated:** 24 Jul 2026
- **Also known as:** DEBIAN-CVE-2026-55626, GHSA-m3xx-cpc4-982r, UBUNTU-CVE-2026-55626

## What is CVE-2026-55626?

CVE-2026-55626 is a high-severity authentication bypass vulnerability in neutrinolabs xrdp, published on 20 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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 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.

Weakness: CWE-306 (Missing Authentication for Critical Functionality), CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-55626?

It affects 1 product.


Products: Neutrinolabs Xrdp.

## How do I fix CVE-2026-55626?

Upgrade to a fixed version.

## Is CVE-2026-55626 being exploited?

There is no known exploitation of CVE-2026-55626 in the wild and no public exploit code.

## Other vulnerabilities in neutrinolabs xrdp

- [CVE-2026-41252](https://insights.sbomify.com/CVE-2026-41252/): xrdp: lib_palette_update Heap Buffer Overflow & RCE (critical 9.8)
- [CVE-2026-32105](https://insights.sbomify.com/CVE-2026-32105/): xrdp: RDP MAC signature (dataSignature) never verified on receive — integrity bypass in non-TLS mode (critical 9.3)
- [CVE-2026-44178](https://insights.sbomify.com/CVE-2026-44178/): xrdp: Channel Data Forwarding Fixed-Size Buffer Overflow (high 8.8)
- [CVE-2026-32107](https://insights.sbomify.com/CVE-2026-32107/): xrdp: Fail-open privilege drop in sesexec — child processes may execute as root if setuid fails (high 8.8)
- [CVE-2026-33689](https://insights.sbomify.com/CVE-2026-33689/): xrdp: Pre-authentication out-of-bounds reads in channel parsers (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55626 and fix it if it is affected.

What it is: CVE-2026-55626 is a high-severity authentication bypass vulnerability in neutrinolabs xrdp, published on 20 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-55626 in the wild and no public exploit code.

Affected product: neutrinolabs xrdp. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-55626/ (Markdown: https://insights.sbomify.com/CVE-2026-55626/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55626
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55626
- OSV: https://osv.dev/vulnerability/CVE-2026-55626

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-55626/
Summaries are generated and may contain mistakes; the official description above is the record.