{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-21521", "assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "state": "PUBLISHED", "assignerShortName": "microsoft", "dateReserved": "2025-12-30T18:10:54.846Z", "datePublished": "2026-01-22T22:47:38.118Z", "dateUpdated": "2026-01-23T01:18:54.276Z"}, "containers": {"cna": {"title": "Word Copilot Information Disclosure Vulnerability", "datePublic": "2026-01-22T08:00:00.000Z", "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:365_word_copilot:*:*:*:*:*:*:*:*", "versionStartIncluding": "-"}]}]}], "affected": [{"vendor": "Microsoft", "product": "Microsoft 365 Word Copilot", "versions": [{"version": "-", "status": "affected"}]}], "descriptions": [{"value": "Improper neutralization of escape, meta, or control sequences in Copilot allows an unauthorized attacker to disclose information over a network.", "lang": "en-US"}], "problemTypes": [{"descriptions": [{"description": "CWE-150: Improper Neutralization of Escape, Meta, or Control Sequences", "lang": "en-US", "type": "CWE", "cweId": "CWE-150"}]}], "providerMetadata": {"orgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "shortName": "microsoft", "dateUpdated": "2026-01-23T01:18:54.276Z"}, "references": [{"name": "Word Copilot Information Disclosure Vulnerability", "tags": ["vendor-advisory", "patch"], "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21521"}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en-US", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "baseSeverity": "HIGH", "baseScore": 7.4, "vectorString": "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"}}], "tags": ["exclusively-hosted-service"]}}}

{}

{"cveTags": [{"sourceIdentifier": "secure@microsoft.com", "tags": ["exclusively-hosted-service"]}], "descriptions": [{"lang": "en", "value": "Improper neutralization of escape, meta, or control sequences in Copilot allows an unauthorized attacker to disclose information over a network."}], "id": "CVE-2026-21521", "lastModified": "2026-01-22T23:15:57.823", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 7.4, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 4.0, "source": "secure@microsoft.com", "type": "Primary"}]}, "published": "2026-01-22T23:15:57.823", "references": [{"source": "secure@microsoft.com", "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21521"}], "sourceIdentifier": "secure@microsoft.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-150"}], "source": "secure@microsoft.com", "type": "Primary"}]}

{}