CVE-2026-26164

High

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.

SeverityHigh

CVSS7.5

Exploit probability57. percentile0.8%

Product

Microsoft 365 Copilot Chat

PublishedMay 7, 2026

First seenMay 7, 2026

Weakness typeCWE-74Injection

How to fix

Patches

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26164

Affected products

Product	Affected versions	Fixed in
microsoft 365_copilot_chat	No range specified	—

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