# CVE-2026-26164: Microsoft M365 Copilot command injection information disclosure

Source: https://junglewise.ai/threats/cve-2026-26164-microsoft-m365-copilot-command-injection-information-disclosure  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-07. Updated: 2026-06-01  
License: CC BY 4.0 with a link back

CVE-2026-26164 · Severity: high · CVSS 7.5 · Published 2026-05-07

Microsoft 365 Copilot, an AI-powered productivity tool, is vulnerable to a command injection flaw. This vulnerability allows an unauthorized person to remotely access and disclose sensitive information over the network. Because this is a hosted service, the impact could involve the exposure of corporate data processed by the AI assistant.

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

## Quick answers

**Is CVE-2026-26164 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-26164 being exploited in the wild.

**How severe is CVE-2026-26164?** High severity, with a CVSS score of 7.5, published 7 May 2026.

**Which products and versions are affected?** Microsoft 365 Copilot All versions (Exclusively Hosted Service).

**Is there a fix for CVE-2026-26164?** 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-2026-26164 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-26164?** Check whether you run Microsoft 365 Copilot or Microsoft 365 Copilot Chat 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 command injection vulnerability exists in Microsoft 365 Copilot due to improper neutralization of special elements used in a command (CWE-74). An unauthenticated attacker can exploit this over the network without user interaction (AV:N/AC:L/PR:N/UI:N). Successful exploitation results in unauthorized information disclosure (Confidentiality: High). As an exclusively hosted service, Microsoft typically manages the remediation on the backend, though the vulnerability was officially disclosed in May 2026.

## Affected products

- Microsoft 365 Copilot All versions (Exclusively Hosted Service)

## Timeline

- 2026-05-07: disclosed: Initial disclosure by Microsoft Corporation
- 2026-05-07: advisory: NVD published the CVE record
- 2026-06-01: other: Description updated to clarify command injection nature

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26164](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26164)

## 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 365 Copilot Business Chat command injection](https://junglewise.ai/threats/cve-2026-78501-microsoft-365-copilot-business-chat-command-injection)
- [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)