RCE in Microsoft Copilot

CVE-2026-55946

Ai command injection in Microsoft Copilot allows an unauthorized attacker to disclose information over a network.

Vulnerability class: Command Injection (OS Command Injection)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (33.1th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 33.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-55946: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-55946?
CVE-2026-55946 is a medium-severity vulnerability in Microsoft Copilot, classified under Command Injection. CVSS score: 6.1/10. Published 2026-09-17.
How severe is CVE-2026-55946?
Medium severity. CVSS v3 base score is 6.1 out of 10.