CVE-2026-24307

CRITICAL

Microsoft 365 Copilot - Unauthenticated Information Disclosure via Improper Input Validation

Title source: llm

Improper validation of specified type of input in M365 Copilot allows an unauthorized attacker to disclose information over a network.

Core 1

Core References

Vendor Advisory vendor-advisory patch

CVSS v3 9.3

EPSS 0.0081

EPSS Percentile 51.9%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

Vulnrichment

Exploitation none

Automatable no

Technical Impact total

CWE

CWE-1287

Status published

Products (2)

microsoft/365_copilot

Microsoft/Microsoft 365 Copilot -

Published Jan 22, 2026

Tracked Since Feb 18, 2026