Vulnerability · Published Jan 22, 2026 · Assigned by microsoft
CVE-2026-21521Word Copilot Information Disclosure Vulnerability
High 7.4
In plain English
A high-severity security flaw in Microsoft 365 Word Copilot from Microsoft. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 50% of all known vulnerabilities).
Severity (CVSS 3.1)7.4High
Exploit odds (30 days)0.6%top 50.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Improper neutralization of escape, meta, or control sequences in Copilot allows an unauthorized attacker to disclose information over a network.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Microsoft 365 Word Copilot | - |
Weakness: CWE-150 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N/E:U/RL:O/RC:C
References
- Word Copilot Information Disclosure Vulnerability vendor-advisory, patch