November 13, 2026 Follow Egret
CVE-2026-120796 · CVE record: PUBLISHED

.NET Denial of Service Vulnerability

Microsoft .NET 11.0 installed on Linux, Microsoft .NET 11.0 installed on Mac OS, Microsoft .NET 11.0 installed on Windows, Microsoft System.Text.Json

Inefficient algorithmic complexity in .NET allows an unauthorized attacker to deny service over a network.

Exploitation evidence

Not listed in the latest downloaded CISA KEV catalog. This does not establish an absence of exploitation.

KEV checked 13 Nov 2026, 00:20 Jerusalem · Original catalog ↗

Reported products and versions

Microsoft / .NET 11.0 installed on Linux

Default status: Not specified

  • affected: 11.0.0-preview.1 to < 11.0.0 (custom)

Microsoft / .NET 11.0 installed on Mac OS

Default status: Not specified

  • affected: 11.0.0-preview.1 to < 11.0.0 (custom)

Microsoft / .NET 11.0 installed on Windows

Default status: Not specified

  • affected: 11.0.0-preview.1 to < 11.0.0 (custom)

Microsoft / System.Text.Json

Default status: Not specified

  • affected: NOT_YET_AVAILABLE to < 11.0.0 (custom)

Fixes and workarounds

No explicit solution text in the downloaded CVE record. Consult the vendor advisory; unaffected version ranges are shown above as reported, not inferred as a patch recommendation.

Sources and related reporting

CVE Program record ↗ · Download tracked evidence as JSON

Monitored source mentions

Shared CVE identifiers link source mentions; they do not establish that the reports describe the same incident.

Observed change timeline

History begins when Egret first downloads each source. It is not the complete upstream CVE history.

12 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-12",
  "epss": 0.01168,
  "percentile": 0.67815
}
12 Nov 2026, 18:20 Jerusalem · CVE Program record changed

Stored CNA snapshot at this observation.

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-120796",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-11-11T01:34:09.164243Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-11-11T01:37:16.139Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": ".NET 11.0 installed on Linux",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "11.0.0",
              "status": "affected",
              "version": "11.0.0-preview.1",
              "versionType": "custom"
            }
          ]
        },
        {
          "product": ".NET 11.0 installed on Mac OS",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "11.0.0",
              "status": "affected",
              "version": "11.0.0-preview.1",
              "versionType": "custom"
            }
          ]
        },
        {
          "product": ".NET 11.0 installed on Windows",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "11.0.0",
              "status": "affected",
              "version": "11.0.0-preview.1",
              "versionType": "custom"
            }
          ]
        },
        {
          "product": "System.Text.Json",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "11.0.0",
              "status": "affected",
              "version": "NOT_YET_AVAILABLE",
              "versionType": "custom"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:microsoft:.net_11.0_installed_on_windows:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "11.0.0",
                  "versionStartIncluding": "11.0.0-preview.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:a:microsoft:.net_11.0_installed_on_linux:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "11.0.0",
                  "versionStartIncluding": "11.0.0-preview.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:a:microsoft:.net_11.0_installed_on_mac_os:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "11.0.0",
                  "versionStartIncluding": "11.0.0-preview.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:a:microsoft:system.text.json:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "11.0.0",
                  "versionStartIncluding": "NOT_YET_AVAILABLE",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "datePublic": "2026-11-10T16:00:00.000Z",
      "descriptions": [
        {
          "lang": "en-US",
          "value": "Inefficient algorithmic complexity in .NET allows an unauthorized attacker to deny service over a network."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en-US",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-407",
              "description": "CWE-407: Inefficient Algorithmic Complexity",
              "lang": "en-US",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-12T15:48:55.869Z",
        "orgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8",
        "shortName": "microsoft"
      },
      "references": [
        {
          "name": ".NET Denial of Service Vulnerability",
          "tags": [
            "vendor-advisory",
            "patch"
          ],
          "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-120796"
        }
      ],
      "title": ".NET Denial of Service Vulnerability"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8",
    "assignerShortName": "microsoft",
    "cveId": "CVE-2026-120796",
    "datePublished": "2026-11-10T18:23:53.968Z",
    "dateReserved": "2026-11-02T22:42:10.893Z",
    "dateUpdated": "2026-11-12T15:48:55.869Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}
11 Nov 2026, 12:20 Jerusalem · CVE Program record changed

Stored CNA snapshot at this observation.

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-120796",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-11-11T01:34:09.164243Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-11-11T01:37:16.139Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": ".NET 11.0 installed on Linux",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "11.0.0",
              "status": "affected",
              "version": "11.0.0-preview.1",
              "versionType": "custom"
            }
          ]
        },
        {
          "product": ".NET 11.0 installed on Mac OS",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "11.0.0",
              "status": "affected",
              "version": "11.0.0-preview.1",
              "versionType": "custom"
            }
          ]
        },
        {
          "product": ".NET 11.0 installed on Windows",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "11.0.0",
              "status": "affected",
              "version": "11.0.0-preview.1",
              "versionType": "custom"
            }
          ]
        },
        {
          "product": "System.Text.Json",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "11.0.0",
              "status": "affected",
              "version": "NOT_YET_AVAILABLE",
              "versionType": "custom"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:microsoft:.net_11.0_installed_on_windows:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "11.0.0",
                  "versionStartIncluding": "11.0.0-preview.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:a:microsoft:.net_11.0_installed_on_linux:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "11.0.0",
                  "versionStartIncluding": "11.0.0-preview.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:a:microsoft:.net_11.0_installed_on_mac_os:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "11.0.0",
                  "versionStartIncluding": "11.0.0-preview.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:a:microsoft:system.text.json:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "11.0.0",
                  "versionStartIncluding": "NOT_YET_AVAILABLE",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "datePublic": "2026-11-10T16:00:00.000Z",
      "descriptions": [
        {
          "lang": "en-US",
          "value": "Inefficient algorithmic complexity in .NET allows an unauthorized attacker to deny service over a network."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en-US",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-407",
              "description": "CWE-407: Inefficient Algorithmic Complexity",
              "lang": "en-US",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-10T23:55:28.221Z",
        "orgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8",
        "shortName": "microsoft"
      },
      "references": [
        {
          "name": ".NET Denial of Service Vulnerability",
          "tags": [
            "vendor-advisory",
            "patch"
          ],
          "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-120796"
        }
      ],
      "title": ".NET Denial of Service Vulnerability"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8",
    "assignerShortName": "microsoft",
    "cveId": "CVE-2026-120796",
    "datePublished": "2026-11-10T18:23:53.968Z",
    "dateReserved": "2026-11-02T22:42:10.893Z",
    "dateUpdated": "2026-11-11T01:37:16.139Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}
Egret — Back to top Egret