Vulnerability · Published Sep 17, 2026 · Assigned by microsoft
CVE-2026-78501Microsoft 365 Copilot Business Chat Information Disclosure Vulnerability
High 8.6
In plain English
A high-severity command injection in Microsoft 365 Copilot's Business Chat from Microsoft. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 46% of all known vulnerabilities).
Severity (CVSS 3.1)8.6High
Exploit odds (30 days)0.5%top 54.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Improper neutralization of special elements used in a command ('command injection') in Microsoft 365 Copilot's Business Chat allows an unauthorized attacker to disclose information over a network.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Microsoft 365 Copilot's Business Chat | - |
Weakness: CWE-77, CWE-923 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N/E:U/RL:O/RC:C
References
- Microsoft 365 Copilot Business Chat Information Disclosure Vulnerability vendor-advisory, patch