Vulnerability-Lookup

CERTFR-2026-AVI-0151

Vulnerability from certfr_avis - Published: 2026-02-11 - Updated: 2026-02-11

Une vulnérabilité a été découverte dans Microsoft .Net. Elle permet à un attaquant de provoquer un contournement de la politique de sécurité.

Solutions

Se référer au bulletin de sécurité de l'éditeur pour l'obtention des correctifs (cf. section Documentation).

None

Impacted products

Vendor	Product	Description
Microsoft	N/A	.NET 8.0 installed sur Mac OS versions antérieures à 8.0.24
Microsoft	N/A	.NET 9.0 installed sur Linux versions antérieures à 9.0.13
Microsoft	N/A	.NET 10.0 installed sur Mac OS versions antérieures à 10.0.3
Microsoft	N/A	.NET 10.0 installed sur Linux versions antérieures à 10.0.3
Microsoft	N/A	.NET 8.0 installed sur Linux versions antérieures à 8.0.24
Microsoft	N/A	.NET 9.0 installed sur Mac OS versions antérieures à 9.0.13

References

Title

Publication Time

Tags

Bulletin de sécurité Microsoft .Net CVE-2026-21218

2026-02-10

vendor-advisory

Show details on source website

JSON

To clipboard

{
  "$ref": "https://www.cert.ssi.gouv.fr/openapi.json",
  "affected_systems": [
    {
      "description": ".NET 8.0 installed sur Mac OS versions ant\u00e9rieures \u00e0 8.0.24",
      "product": {
        "name": "N/A",
        "vendor": {
          "name": "Microsoft",
          "scada": false
        }
      }
    },
    {
      "description": ".NET 9.0 installed sur Linux versions ant\u00e9rieures \u00e0 9.0.13",
      "product": {
        "name": "N/A",
        "vendor": {
          "name": "Microsoft",
          "scada": false
        }
      }
    },
    {
      "description": ".NET 10.0 installed sur Mac OS versions ant\u00e9rieures \u00e0 10.0.3",
      "product": {
        "name": "N/A",
        "vendor": {
          "name": "Microsoft",
          "scada": false
        }
      }
    },
    {
      "description": ".NET 10.0 installed sur Linux versions ant\u00e9rieures \u00e0 10.0.3",
      "product": {
        "name": "N/A",
        "vendor": {
          "name": "Microsoft",
          "scada": false
        }
      }
    },
    {
      "description": ".NET 8.0 installed sur Linux versions ant\u00e9rieures \u00e0 8.0.24",
      "product": {
        "name": "N/A",
        "vendor": {
          "name": "Microsoft",
          "scada": false
        }
      }
    },
    {
      "description": ".NET 9.0 installed sur Mac OS versions ant\u00e9rieures \u00e0 9.0.13",
      "product": {
        "name": "N/A",
        "vendor": {
          "name": "Microsoft",
          "scada": false
        }
      }
    }
  ],
  "affected_systems_content": null,
  "content": "## Solutions\n\nSe r\u00e9f\u00e9rer au bulletin de s\u00e9curit\u00e9 de l\u0027\u00e9diteur pour l\u0027obtention des correctifs (cf. section Documentation).",
  "cves": [
    {
      "name": "CVE-2026-21218",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-21218"
    }
  ],
  "initial_release_date": "2026-02-11T00:00:00",
  "last_revision_date": "2026-02-11T00:00:00",
  "links": [],
  "reference": "CERTFR-2026-AVI-0151",
  "revisions": [
    {
      "description": "Version initiale",
      "revision_date": "2026-02-11T00:00:00.000000"
    }
  ],
  "risks": [
    {
      "description": "Contournement de la politique de s\u00e9curit\u00e9"
    }
  ],
  "summary": "Une vuln\u00e9rabilit\u00e9 a \u00e9t\u00e9 d\u00e9couverte dans Microsoft .Net. Elle permet \u00e0 un attaquant de provoquer un contournement de la politique de s\u00e9curit\u00e9.",
  "title": "Vuln\u00e9rabilit\u00e9 dans Microsoft .Net",
  "vendor_advisories": [
    {
      "published_at": "2026-02-10",
      "title": "Bulletin de s\u00e9curit\u00e9 Microsoft .Net CVE-2026-21218",
      "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21218"
    }
  ]
}

CVE-2026-21218 (GCVE-0-2026-21218)

Vulnerability from cvelistv5 – Published: 2026-02-10 17:51 – Updated: 2026-02-13 22:30

Title

.NET Spoofing Vulnerability

Summary

Improper handling of missing special element in .NET allows an unauthorized attacker to perform spoofing over a network.

Severity ?

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C

CWE

CWE-166 - Improper Handling of Missing Special Element

Assigner

microsoft

References

URL

Tags

https://msrc.microsoft.com/update-guide/vulnerabi…

vendor-advisorypatch

Impacted products

Vendor

Product

Version

Microsoft

.NET 10.0

Affected: 10.0.0 , < 10.0.3 (custom)

	Microsoft	.NET 8.0	Affected: 8.0.0 , < 8.0.24 (custom)
	Microsoft	.NET 9.0	Affected: 9.0.0 , < 9.0.13 (custom)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-21218",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-02-11T15:29:08.823948Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-02-11T15:29:32.930Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": ".NET 10.0",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "10.0.3",
              "status": "affected",
              "version": "10.0.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "product": ".NET 8.0",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "8.0.24",
              "status": "affected",
              "version": "8.0.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "product": ".NET 9.0",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "9.0.13",
              "status": "affected",
              "version": "9.0.0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "10.0.3",
                  "versionStartIncluding": "10.0.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "8.0.24",
                  "versionStartIncluding": "8.0.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "9.0.13",
                  "versionStartIncluding": "9.0.0",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "datePublic": "2026-02-10T08:00:00.000Z",
      "descriptions": [
        {
          "lang": "en-US",
          "value": "Improper handling of missing special element in .NET allows an unauthorized attacker to perform spoofing over a network."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en-US",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-166",
              "description": "CWE-166: Improper Handling of Missing Special Element",
              "lang": "en-US",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-02-13T22:30:22.326Z",
        "orgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8",
        "shortName": "microsoft"
      },
      "references": [
        {
          "name": ".NET Spoofing Vulnerability",
          "tags": [
            "vendor-advisory",
            "patch"
          ],
          "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21218"
        }
      ],
      "title": ".NET Spoofing Vulnerability"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8",
    "assignerShortName": "microsoft",
    "cveId": "CVE-2026-21218",
    "datePublished": "2026-02-10T17:51:23.973Z",
    "dateReserved": "2025-12-11T21:02:05.731Z",
    "dateUpdated": "2026-02-13T22:30:22.326Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

Nomenclature

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.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
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.

Action not permitted

CERTFR-2026-AVI-0151

Solutions

CVE-2026-21218 (GCVE-0-2026-21218)

Tags

Sightings

Nomenclature