# CVE-2026-33689: xrdp: Pre-authentication out-of-bounds reads in channel parsers

> Remote unauthenticated attackers can cause denial of service or disclose sensitive memory information in xrdp via crafted packets.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Apr 2026
- **Updated:** 20 Apr 2026
- **Also known as:** DEBIAN-CVE-2026-33689, GHSA-92mr-6wpp-27jj, UBUNTU-CVE-2026-33689

## What is CVE-2026-33689?

CVE-2026-33689 is a high-severity vulnerability in neutrinolabs xrdp, published on 17 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

xrdp is an open source RDP server. Versions through 0.10.5 have an out-of-bounds read vulnerability in the pre-authentication RDP message parsing logic. A remote, unauthenticated attacker can trigger this flaw by sending a specially crafted sequence of packets during the initial connection phase. This vulnerability results from insufficient validation of input buffer lengths before processing dynamic channel communication. Successful exploitation can lead to a denial-of-service (DoS) condition via a process crash or potential disclosure of sensitive information from the service's memory space. This issue has been fixed in version 0.10.6.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-33689?

It affects 1 product.


Products: Neutrinolabs Xrdp.

## How do I fix CVE-2026-33689?

Upgrade to a fixed version.

## Is CVE-2026-33689 being exploited?

There is no known exploitation of CVE-2026-33689 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-2026-35512](https://insights.sbomify.com/CVE-2026-35512/): xrdp: Heap buffer overflow in EGFX channel (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33689 and fix it if it is affected.

What it is: CVE-2026-33689 is a high-severity vulnerability in neutrinolabs xrdp, published on 17 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-33689 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-2026-33689/ (Markdown: https://insights.sbomify.com/CVE-2026-33689/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33689
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33689
- OSV: https://osv.dev/vulnerability/CVE-2026-33689

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33689/
Summaries are generated and may contain mistakes; the official description above is the record.