# CVE-2026-80077: Microsoft Remote Desktop Client heap buffer overflow

Source: https://junglewise.ai/threats/cve-2026-80077-microsoft-remote-desktop-client-heap-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-2026-80077 · Severity: high · CVSS 8.8 · Published 2026-09-08

Microsoft Remote Desktop Client is a tool used to access and control computers remotely over a network. A heap-based buffer overflow vulnerability in this software allows an attacker to execute arbitrary code on a victim's machine without authorization, potentially leading to complete system compromise and unauthorized access to sensitive data.

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-2026-80077 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-80077 being exploited in the wild.

**How severe is CVE-2026-80077?** High severity, with a CVSS score of 8.8, published 8 September 2026.

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

**Is there a fix for CVE-2026-80077?** 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-2026-80077 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-80077?** Check whether you run Microsoft Remote Desktop Client. 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

This is a heap-based buffer overflow vulnerability in the Remote Desktop Client protocol handling code. The vulnerability can be exploited over the network without authentication or user interaction, allowing an attacker to send a specially crafted RDP message that triggers memory corruption. Successful exploitation results in arbitrary code execution with the privileges of the user running the Remote Desktop Client. The attack vector is network-based, making it remotely exploitable.

## Affected products

- Microsoft Remote Desktop Client

## Timeline

- 2026-09-08: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-80077](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-80077)

## Related threats

- [Microsoft Remote Desktop Client race condition code execution](https://junglewise.ai/threats/cve-2026-95964-concurrent-execution-using-shared-resource-with-improper)
- [Microsoft Remote Desktop Client out-of-bounds read](https://junglewise.ai/threats/cve-2026-95908-out-of-bounds-read-in-remote-desktop-client-allows-an-authorized)
- [Microsoft Remote Desktop Client out-of-bounds read](https://junglewise.ai/threats/cve-2026-121678-out-of-bounds-read-in-remote-desktop-client-allows-an)
- [Microsoft Remote Desktop Client out-of-bounds read](https://junglewise.ai/threats/cve-2026-121677-out-of-bounds-read-in-remote-desktop-client-allows-an)
- [Microsoft Remote Desktop Client double free memory corruption](https://junglewise.ai/threats/cve-2026-119934-double-free-in-remote-desktop-client-allows-an-unauthorized)