What is CVE-2026-55145?

CVE-2026-55145 is a medium-severity vulnerability in Microsoft Copilot, classified under Command Injection. CVSS score: 6.3/10. Published 2026-07-14.

How severe is CVE-2026-55145?

Medium severity. CVSS v3 base score is 6.3 out of 10.

RCE in Microsoft Copilot

CVE-2026-55145

Improper neutralization of special elements used in a command ('command injection') in Outlook Copilot allows an authorized attacker to perform tampering over a network.

Vulnerability class: Command Injection (OS Command Injection)

EPSS: 0.005 (42.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N.

Affected products

Microsoft Copilot
Microsoft Copilot

Weakness classification (CWE)

CWE-77 — Command Injection

References

Outlook Copilot Tampering Vulnerability (vendor-advisory, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-55145?: CVE-2026-55145 is a medium-severity vulnerability in Microsoft Copilot, classified under Command Injection. CVSS score: 6.3/10. Published 2026-07-14.
How severe is CVE-2026-55145?: Medium severity. CVSS v3 base score is 6.3 out of 10.