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