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TI-2026-17375 Aliases CVE-2026-21521GHSA-mmfw-g245-wgx2

Word Copilot Information Disclosure Vulnerability

Priority LOW 33CWE-150Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from Microsoft.

Summary

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

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00613 49th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MicrosoftMicrosoft 365 Word Copilot-—No fix listedCNA
  • Microsoft 365 Word Copilot VendorMicrosoft Affected - Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:microsoft:365_word_copilot:-:*:*:*:*:*:*:*not specified by NVDVulnerableMicrosoft
  • cpe:2.3:a:microsoft:365_word_copilot:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Microsoft

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Microsoft

Microsoft's page for this CVE →

Impact
Information Disclosure
Exploited
No
Publicly disclosed
No
Exploitability
—

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-21521
  2. 2026-10-03 Alias added: GHSA-mmfw-g245-wgx2

References

Patch 1

  • TI-2025-36839 M365 Copilot Information Disclosure Vulnerability CVSS 3.1CRITICAL 9.3

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences