Vulnerability-Lookup

CVE-2026-81766 (GCVE-0-2026-81766)

Vulnerability from cvelistv5 – Published: 2026-08-30 06:00 – Updated: 2026-08-31 12:38

Title

Really Simple Security < 9.8.0 - Multisite Subsite Admin+ Arbitrary Plugin Installation via rsp_upgrade_install_plugin

Summary

The Really Simple Security WordPress plugin before 9.8.0 does not check that the user is allowed to install Really Simple Security WordPress plugin before 9.8.0 before installing one from a user-supplied URL, allowing an administrator of a subsite on a multisite network to install and execute arbitrary code in the network-shared Really Simple Security WordPress plugin before 9.8.0 directory, which WordPress otherwise reserves to the network administrator. Exploitation requires the network administrator to have enabled the Really Simple Security WordPress plugin before 9.8.0 administration menu for subsites, which is not the default.

Severity

6.6 (Medium)


                        
                          CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-31 12:30 UTC

CWE

CWE-269 Improper Privilege Management
CWE-269 - Improper Privilege Management

Assigner

WPScan mitre root

References

1 reference

URL	Tags
https://wpscan.com/vulnerability/948d70a2-605e-4a…	exploitvdb-entrytechnical-description

Impacted products

1 product

Vendor	Product	Version	CPE status
Unknown	Really Simple Security	Affected: 0 , < 9.8.0 (semver)	guessed

Credits

Charles Vosburgh WPScan

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "HIGH",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 6.6,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
              "privilegesRequired": "HIGH",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-81766",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-31T12:30:08.806418Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-269",
                "description": "CWE-269 Improper Privilege Management",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-31T12:38:05.969Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Really Simple Security",
          "vendor": "Unknown",
          "versions": [
            {
              "lessThan": "9.8.0",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Charles Vosburgh"
        },
        {
          "lang": "en",
          "type": "coordinator",
          "value": "WPScan"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The Really Simple Security  WordPress plugin before 9.8.0 does not check that the user is allowed to install Really Simple Security  WordPress plugin before 9.8.0 before installing one from a user-supplied URL, allowing an administrator of a subsite on a multisite network to install and execute arbitrary code in the network-shared Really Simple Security  WordPress plugin before 9.8.0 directory, which WordPress otherwise reserves to the network administrator. Exploitation requires the network administrator to have enabled the Really Simple Security  WordPress plugin before 9.8.0 administration menu for subsites, which is not the default."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-269 Improper Privilege Management",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-30T06:00:18.989Z",
        "orgId": "1bfdd5d7-9bf6-4a53-96ea-42e2716d7a81",
        "shortName": "WPScan"
      },
      "references": [
        {
          "tags": [
            "exploit",
            "vdb-entry",
            "technical-description"
          ],
          "url": "https://wpscan.com/vulnerability/948d70a2-605e-4a83-8feb-eca4dbb5f948/"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "Really Simple Security \u003c 9.8.0 - Multisite Subsite Admin+ Arbitrary Plugin Installation via rsp_upgrade_install_plugin",
      "x_generator": {
        "engine": "WPScan CVE Generator"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bfdd5d7-9bf6-4a53-96ea-42e2716d7a81",
    "assignerShortName": "WPScan",
    "cveId": "CVE-2026-81766",
    "datePublished": "2026-08-30T06:00:18.989Z",
    "dateReserved": "2026-08-27T12:23:16.066Z",
    "dateUpdated": "2026-08-31T12:38:05.969Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-81766",
      "date": "2026-09-01",
      "epss": "0.00257",
      "percentile": "0.17104"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-81766\",\"sourceIdentifier\":\"contact@wpscan.com\",\"published\":\"2026-08-30T07:17:21.890\",\"lastModified\":\"2026-08-31T20:14:36.250\",\"vulnStatus\":\"Deferred\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"The Really Simple Security  WordPress plugin before 9.8.0 does not check that the user is allowed to install Really Simple Security  WordPress plugin before 9.8.0 before installing one from a user-supplied URL, allowing an administrator of a subsite on a multisite network to install and execute arbitrary code in the network-shared Really Simple Security  WordPress plugin before 9.8.0 directory, which WordPress otherwise reserves to the network administrator. Exploitation requires the network administrator to have enabled the Really Simple Security  WordPress plugin before 9.8.0 administration menu for subsites, which is not the default.\"}],\"affected\":[{\"source\":\"contact@wpscan.com\",\"affectedData\":[{\"vendor\":\"Unknown\",\"product\":\"Really Simple Security\",\"defaultStatus\":\"unaffected\",\"versions\":[{\"version\":\"0\",\"lessThan\":\"9.8.0\",\"versionType\":\"semver\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":6.6,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"HIGH\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":0.7,\"impactScore\":5.9}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-08-31T12:30:08.806418Z\",\"id\":\"CVE-2026-81766\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"total\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-269\"}]}],\"references\":[{\"url\":\"https://wpscan.com/vulnerability/948d70a2-605e-4a83-8feb-eca4dbb5f948/\",\"source\":\"contact@wpscan.com\"}]}}",
    "vulnrichment": {
      "containers": "{\"cna\": {\"title\": \"Really Simple Security \u003c 9.8.0 - Multisite Subsite Admin+ Arbitrary Plugin Installation via rsp_upgrade_install_plugin\", \"source\": {\"discovery\": \"EXTERNAL\"}, \"credits\": [{\"lang\": \"en\", \"type\": \"finder\", \"value\": \"Charles Vosburgh\"}, {\"lang\": \"en\", \"type\": \"coordinator\", \"value\": \"WPScan\"}], \"affected\": [{\"vendor\": \"Unknown\", \"product\": \"Really Simple Security\", \"versions\": [{\"status\": \"affected\", \"version\": \"0\", \"lessThan\": \"9.8.0\", \"versionType\": \"semver\"}], \"defaultStatus\": \"unaffected\"}], \"references\": [{\"url\": \"https://wpscan.com/vulnerability/948d70a2-605e-4a83-8feb-eca4dbb5f948/\", \"tags\": [\"exploit\", \"vdb-entry\", \"technical-description\"]}], \"x_generator\": {\"engine\": \"WPScan CVE Generator\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"The Really Simple Security  WordPress plugin before 9.8.0 does not check that the user is allowed to install Really Simple Security  WordPress plugin before 9.8.0 before installing one from a user-supplied URL, allowing an administrator of a subsite on a multisite network to install and execute arbitrary code in the network-shared Really Simple Security  WordPress plugin before 9.8.0 directory, which WordPress otherwise reserves to the network administrator. Exploitation requires the network administrator to have enabled the Really Simple Security  WordPress plugin before 9.8.0 administration menu for subsites, which is not the default.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"description\": \"CWE-269 Improper Privilege Management\"}]}], \"providerMetadata\": {\"orgId\": \"1bfdd5d7-9bf6-4a53-96ea-42e2716d7a81\", \"shortName\": \"WPScan\", \"dateUpdated\": \"2026-08-30T06:00:18.989Z\"}}, \"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 6.6, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H\", \"integrityImpact\": \"HIGH\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"HIGH\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"HIGH\", \"confidentialityImpact\": \"HIGH\"}}, {\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-81766\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-08-31T12:30:08.806418Z\"}}}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-269\", \"description\": \"CWE-269 Improper Privilege Management\"}]}], \"providerMetadata\": {\"shortName\": \"CISA-ADP\", \"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"dateUpdated\": \"2026-08-31T12:29:59.962Z\"}}]}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-81766\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-08-30T06:00:18.989Z\", \"dateReserved\": \"2026-08-27T12:23:16.066Z\", \"assignerOrgId\": \"1bfdd5d7-9bf6-4a53-96ea-42e2716d7a81\", \"datePublished\": \"2026-08-30T06:00:18.989Z\", \"assignerShortName\": \"WPScan\"}",
      "dataType": "CVE_RECORD",
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  }
}

FKIE_CVE-2026-81766

Vulnerability from fkie_nvd - Published: 2026-08-30 07:17 - Updated: 2026-08-31 20:14

Severity

6.6 (Medium) - CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

Summary

References

	URL	Tags
	contact@wpscan.com	https://wpscan.com/vulnerability/948d70a2-605e-4a83-8feb-eca4dbb5f948/

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Really Simple Security",
          "vendor": "Unknown",
          "versions": [
            {
              "lessThan": "9.8.0",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "contact@wpscan.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The Really Simple Security  WordPress plugin before 9.8.0 does not check that the user is allowed to install Really Simple Security  WordPress plugin before 9.8.0 before installing one from a user-supplied URL, allowing an administrator of a subsite on a multisite network to install and execute arbitrary code in the network-shared Really Simple Security  WordPress plugin before 9.8.0 directory, which WordPress otherwise reserves to the network administrator. Exploitation requires the network administrator to have enabled the Really Simple Security  WordPress plugin before 9.8.0 administration menu for subsites, which is not the default."
    }
  ],
  "id": "CVE-2026-81766",
  "lastModified": "2026-08-31T20:14:36.250",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 6.6,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "HIGH",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 0.7,
        "impactScore": 5.9,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-81766",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-08-31T12:30:08.806418Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-30T07:17:21.890",
  "references": [
    {
      "source": "contact@wpscan.com",
      "url": "https://wpscan.com/vulnerability/948d70a2-605e-4a83-8feb-eca4dbb5f948/"
    }
  ],
  "sourceIdentifier": "contact@wpscan.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-269"
        }
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary"
    }
  ]
}

GHSA-C5MG-RWRQ-R34J

Vulnerability from github – Published: 2026-08-30 09:30 – Updated: 2026-08-31 15:34

Details

Severity

6.6 (Medium)


                  
                    CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-81766"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-269"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-30T07:17:21Z",
    "severity": "MODERATE"
  },
  "details": "The Really Simple Security  WordPress plugin before 9.8.0 does not check that the user is allowed to install Really Simple Security  WordPress plugin before 9.8.0 before installing one from a user-supplied URL, allowing an administrator of a subsite on a multisite network to install and execute arbitrary code in the network-shared Really Simple Security  WordPress plugin before 9.8.0 directory, which WordPress otherwise reserves to the network administrator. Exploitation requires the network administrator to have enabled the Really Simple Security  WordPress plugin before 9.8.0 administration menu for subsites, which is not the default.",
  "id": "GHSA-c5mg-rwrq-r34j",
  "modified": "2026-08-31T15:34:39Z",
  "published": "2026-08-30T09:30:24Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-81766"
    },
    {
      "type": "WEB",
      "url": "https://wpscan.com/vulnerability/948d70a2-605e-4a83-8feb-eca4dbb5f948"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

Sightings

Author	Source	Type	Date	Other

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

CVE-2026-81766 (GCVE-0-2026-81766)

FKIE_CVE-2026-81766

GHSA-C5MG-RWRQ-R34J

Tags

Sightings

Nomenclature