CVE-2026-21521

HIGH

Microsoft 365 Word Copilot - Information Disclosure via Improper Neutralization of Escape Sequences

Title source: llm
STIX 2.1

Description

Improper neutralization of escape, meta, or control sequences in Copilot allows an unauthorized attacker to disclose information over a network.

References (1)

Core 1
Core References

Scores

CVSS v3 7.4
EPSS 0.0012
EPSS Percentile 31.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-150
Status published
Products (2)
microsoft/365_word_copilot
Microsoft/Microsoft 365 Word Copilot -
Published Jan 22, 2026
Tracked Since Feb 18, 2026