# CVE-2026-83998: Microsoft Remote Desktop Client heap-based buffer overflow

Source: https://junglewise.ai/threats/cve-2026-83998-microsoft-remote-desktop-client-heap-based-buffer-overflow  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-08. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-83998 · Severity: high · CVSS 8.8 · Published 2026-09-08

The Remote Desktop Client is a Microsoft application used to connect to and control computers remotely over a network. A heap-based buffer overflow vulnerability allows an attacker to send specially crafted network packets that cause the application to crash or execute malicious code with the privileges of the user running the client.

Technologies: [Microsoft Remote Desktop Client](https://junglewise.ai/threats/technologies/remote-desktop-client). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-83998 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-83998 being exploited in the wild.

**How severe is CVE-2026-83998?** High severity, with a CVSS score of 8.8, published 8 September 2026.

**Which products and versions are affected?** Microsoft Remote Desktop Client <UNKNOWN>.

**Is there a fix for CVE-2026-83998?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-83998 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2026-83998?** Check whether you run Microsoft Remote Desktop Client at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A heap-based buffer overflow exists in the Microsoft Remote Desktop Client's network packet processing logic. The vulnerability is triggered when a remote, unauthenticated attacker sends a specially crafted RDP protocol packet over the network to the client. No user interaction or authentication is required to trigger the overflow. Successful exploitation allows arbitrary code execution in the context of the logged-in user. The attack vector is network-based, meaning the attacker can target vulnerable clients from any network location.

## Affected products

- Microsoft Remote Desktop Client <UNKNOWN>

## Timeline

- 2026-09-08: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83998](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83998)

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