# CVE-2026-22853: FreeRDP has a heap-buffer-overflow in ndr_read_uint8Array

> A heap buffer overflow in FreeRDP's NDR array reader allows attackers to execute arbitrary code or cause denial of service via crafted RDP traffic.

- **Severity:** Medium 6.8 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 14 Jan 2026
- **Updated:** 19 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-22853, GHSA-47v9-p4gp-w5ch, MINI-pfcq-gjm4-cvfx, UBUNTU-CVE-2026-22853

## What is CVE-2026-22853?

CVE-2026-22853 is a medium-severity memory corruption vulnerability in Freerdp Freerdp, published on 14 Jan 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, RDPEAR’s NDR array reader does not perform bounds checking on the on‑wire element count and can write past the heap buffer allocated from hints, causing a heap buffer overflow in ndr_read_uint8Array. This vulnerability is fixed in 3.20.1.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-22853?

It affects 1 product.


Products: Freerdp Freerdp.

## How do I fix CVE-2026-22853?

Upgrade to a fixed version.

## Is CVE-2026-22853 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-22853 exists.

## Other vulnerabilities in Freerdp Freerdp

- [CVE-2021-37594](https://insights.sbomify.com/CVE-2021-37594/): Other in n/a (critical 9.8)
- [CVE-2021-37595](https://insights.sbomify.com/CVE-2021-37595/): Other in n/a (critical 9.8)
- [CVE-2026-67305](https://insights.sbomify.com/CVE-2026-67305/): FreeRDP Windows Client before 3.29.0 Heap Buffer Overflow via Cliprdr (critical 9.4)
- [CVE-2026-66402](https://insights.sbomify.com/CVE-2026-66402/): FreeRDP before 3.29.0 TLS Certificate Identity Validation Bypass (critical 9.3)
- [CVE-2026-67289](https://insights.sbomify.com/CVE-2026-67289/): FreeRDP before 3.29.0 HTTP Proxy Request Injection via Redirection (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-22853 and fix it if it is affected.

What it is: CVE-2026-22853 is a medium-severity memory corruption vulnerability in Freerdp Freerdp, published on 14 Jan 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-22853 exists.

Affected product: Freerdp Freerdp. 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-2026-22853/ (Markdown: https://insights.sbomify.com/CVE-2026-22853/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-22853
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-22853
- OSV: https://osv.dev/vulnerability/CVE-2026-22853

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-22853/
Summaries are generated and may contain mistakes; the official description above is the record.