Vulnerability · Published May 7, 2026 · Assigned by microsoft
CVE-2026-26129M365 Copilot Information Disclosure Vulnerability
High 7.5
In plain English
A high-severity security flaw 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 1.1% (higher than 67% of all known vulnerabilities).
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)1.1%top 33.3% 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 M365 Copilot 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-138 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
References
- M365 Copilot Information Disclosure Vulnerability vendor-advisory, patch