# CVE-2026-78501: Microsoft 365 Copilot Business Chat command injection

Source: https://junglewise.ai/threats/cve-2026-78501-microsoft-365-copilot-business-chat-command-injection  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-17. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-78501 · Severity: high · CVSS 7.4 · Published 2026-09-17

Microsoft 365 Copilot's Business Chat feature is vulnerable to command injection, which allows an attacker to inject malicious commands that execute in the context of the application. This could enable unauthorized disclosure of sensitive business information or data accessible to the affected user's account.

Technologies: [Microsoft 365 Copilot](https://junglewise.ai/threats/technologies/365-copilot). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-78501 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-78501 being exploited in the wild.

**How severe is CVE-2026-78501?** High severity, with a CVSS score of 7.4, published 17 September 2026.

**Which products and versions are affected?** Microsoft 365 Copilot <UNKNOWN>.

**Is there a fix for CVE-2026-78501?** 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-2026-78501 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-78501?** Check whether you run Microsoft 365 Copilot 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

The vulnerability is a command injection flaw in Microsoft 365 Copilot's Business Chat component that fails to properly neutralize special elements used in commands. An unauthenticated attacker can exploit this over the network to execute arbitrary commands and access confidential information. The vulnerability has a CVSS score of 7.4 and does not require user interaction or prior authentication. Microsoft has released security updates to address this issue.

## Affected products

- Microsoft 365 Copilot <UNKNOWN>

## Timeline

- 2026-09-17: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-78501](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-78501)

## Related threats

- [Microsoft Graphics Component stack buffer overflow](https://junglewise.ai/threats/cve-2026-85881-stack-based-buffer-overflow-in-microsoft-graphics-component)
- [Microsoft M365 Copilot command injection privilege escalation](https://junglewise.ai/threats/cve-2026-85885-improper-neutralization-of-special-elements-used-in-a-command)
- [Microsoft Copilot command injection in mobile applications](https://junglewise.ai/threats/cve-2026-48561-microsoft-copilot-command-injection-in-mobile-applications)
- [Microsoft M365 Copilot open redirect privilege escalation](https://junglewise.ai/threats/cve-2026-41106-microsoft-m365-copilot-open-redirect-privilege-escalation)
- [Microsoft Copilot command injection](https://junglewise.ai/threats/cve-2026-42895-microsoft-copilot-command-injection)