# CVE-2026-33145: xrdp: Authenticated RCE via unsanitized AlternateShell execution in xrdp-sesman

> Authenticated attackers can execute arbitrary commands on xrdp servers via unsanitized AlternateShell parameters during session initialization.

- **Severity:** Medium 6.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Apr 2026
- **Updated:** 22 Apr 2026
- **Also known as:** DEBIAN-CVE-2026-33145, GHSA-rmvv-7633-fg7h, UBUNTU-CVE-2026-33145

## What is CVE-2026-33145?

CVE-2026-33145 is a medium-severity command injection vulnerability in neutrinolabs xrdp, published on 17 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

xrdp is an open source RDP server. Versions through 0.10.5 allow an authenticated remote user to execute arbitrary commands on the server due to unsafe handling of the AlternateShell parameter in xrdp-sesman. When the AllowAlternateShell setting is enabled (which is the default when not explicitly configured), xrdp accepts a client-supplied AlternateShell value and executes it via /bin/sh -c during session initialization. This results in shell-interpreted execution of unsanitized, user-controlled input. This behavior effectively provides a scriptable remote command execution primitive over RDP within the security context of the authenticated user, occurring prior to normal window manager startup. This can bypass expected session initialization flows and operational assumptions that restrict execution to interactive desktop environments. This issue has been fixed in version 0.10.6.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2026-33145?

It affects 1 product.


Products: Neutrinolabs Xrdp.

## How do I fix CVE-2026-33145?

Upgrade to a fixed version.

## Is CVE-2026-33145 being exploited?

There is no known exploitation of CVE-2026-33145 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-2026-33145 and fix it if it is affected.

What it is: CVE-2026-33145 is a medium-severity command injection vulnerability in neutrinolabs xrdp, published on 17 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-33145 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-2026-33145/ (Markdown: https://insights.sbomify.com/CVE-2026-33145/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33145
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33145
- OSV: https://osv.dev/vulnerability/CVE-2026-33145

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33145/
Summaries are generated and may contain mistakes; the official description above is the record.