What’s Vulnerable › Vulnerabilities

CVE-2026-21521: Word Copilot Information Disclosure Vulnerability

• Severity: high (CVSS 7.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-01-22 · updated 2026-07-30
• Weakness: CWE-150

Description

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

Affected products

• Microsoft 365 Word Copilot: all versions
• Microsoft 365 Word Copilot: all versions

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21521

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