Vulnerability details
CVE-2026-26164
Microsoft 365 Copilot's Business Chat
M365 Copilot Information Disclosure Vulnerability
CVSS 3.1
7.5High
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.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 7.5High | 3.1 | CVEProject cvelistV5 (CNA) (microsoft) | 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 |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| Microsoft | Microsoft 365 Copilot's Business Chat | All | CVEProject cvelistV5 (CNA) |
References and advisories
1- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26164 vendor-advisorypatch
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Details
- Published
- 2026-05-08
- Last updated
- 2026-08-10
- State
- Published
- Assigner (CNA)
- microsoft
Exploit prediction (EPSS)
0.79%
Probability of exploitation in 30 days
56.7%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- Yes
- Exploitation
- None
- Technical impact
- Partial
Weaknesses (CWE)
- CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')