FKIE_CVE-2026-21521

Vulnerability from fkie_nvd - Published: 2026-01-22 23:15 - Updated: 2026-02-02 13:30
Severity ?
7.4 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N
Summary
Improper neutralization of escape, meta, or control sequences in Copilot allows an unauthorized attacker to disclose information over a network.
References
secure@microsoft.comhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21521Vendor Advisory
Impacted products
Vendor Product Version
microsoft 365_word_copilot -
To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:microsoft:365_word_copilot:-:*:*:*:*:*:*:*",
              "matchCriteriaId": "3A538269-3D01-41B4-B8B1-B70D8514D336",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "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": "2026-02-02T13:30:53.350",
  "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",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21521"
    }
  ],
  "sourceIdentifier": "secure@microsoft.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-150"
        }
      ],
      "source": "secure@microsoft.com",
      "type": "Primary"
    }
  ]
}


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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.