CVE-2026-8350 (GCVE-0-2026-8350)

Vulnerability from cvelistv5 – Published: 2026-05-21 20:28 – Updated: 2026-05-22 13:22
VLAI
Title
Concrete CMS 9.5.0 and below is vulnerable to missing authorization in the bulk_user_assignment.php which can lead to privilege escalation to Administrative Group
Summary
Concrete CMS 9.5.0 and below is vulnerable to missing authorization in the bulk_user_assignment.php which can lead to privilege escalation to Administrative Group. Any authenticated user with access to the bulk user assignment dashboard page can add any user email to any group and can remove legitimate admins. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 7.5 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Vincent55 for reporting.
Severity
7.5 (High)
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
SSVC
Exploitation: none Automatable: no Technical Impact: total
CISA Coordinator (v2.0.3)
CWE
Assigner
References
Impacted products
Vendor Product Version
Concrete CMS Concrete CMS Affected: 5.0 , ≤ 9.5.0 (git)
Create a notification for this product.
Credits
Vincent55
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-8350",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-22T13:22:41.872694Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-22T13:22:50.510Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://github.com/concretecms/concretecms",
          "defaultStatus": "unaffected",
          "product": "Concrete CMS",
          "repo": "https://github.com/concretecms/concretecms",
          "vendor": "Concrete CMS",
          "versions": [
            {
              "lessThanOrEqual": "9.5.0",
              "status": "affected",
              "version": "5.0",
              "versionType": "git"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Vincent55"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cdiv\u003e\u003cbr\u003e\u003c/div\u003e\u003cdiv\u003eConcrete CMS 9.5.0 and below is vulnerable to m\u003cspan\u003eissing authorization in the bulk_user_assignment.php which can lead to privilege escalation\u0026nbsp;\u003c/span\u003eto Administrative Group\u003cspan\u003e.\u0026nbsp;\u003c/span\u003e\u003cspan\u003eAny authenticated user with access to the bulk user assignment dashboard page can add any user email to any group and can remove legitimate admins.\u003c/span\u003e\u0026nbsp;\u003cspan\u003eThe Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 7.5 with vector\u0026nbsp;\u003c/span\u003eCVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N\u003cspan\u003e. Thanks\u0026nbsp;Vincent55 for reporting.\u0026nbsp;\u003c/span\u003e\u003c/div\u003e"
            }
          ],
          "value": "Concrete CMS 9.5.0 and below is vulnerable to missing authorization in the bulk_user_assignment.php which can lead to privilege escalation\u00a0to Administrative Group.\u00a0Any authenticated user with access to the bulk user assignment dashboard page can add any user email to any group and can remove legitimate admins.\u00a0The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 7.5 with vector\u00a0CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks\u00a0Vincent55 for reporting."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-1",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-1 Accessing Functionality Not Properly Constrained by ACLs"
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "HIGH",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-863",
              "description": "CWE-863",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-21T20:28:03.032Z",
        "orgId": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "shortName": "ConcreteCMS"
      },
      "references": [
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes"
        }
      ],
      "source": {
        "advisory": "https://hackerone.com/reports/3594435",
        "defect": [
          "HackerONE"
        ],
        "discovery": "EXTERNAL"
      },
      "title": "Concrete CMS 9.5.0 and below is vulnerable to missing authorization in the bulk_user_assignment.php which can lead to privilege escalation to Administrative Group",
      "x_generator": {
        "engine": "Vulnogram 1.0.2"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
    "assignerShortName": "ConcreteCMS",
    "cveId": "CVE-2026-8350",
    "datePublished": "2026-05-21T20:28:03.032Z",
    "dateReserved": "2026-05-11T16:40:39.812Z",
    "dateUpdated": "2026-05-22T13:22:50.510Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-8350",
      "date": "2026-06-04",
      "epss": "0.00031",
      "percentile": "0.09387"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-8350\",\"sourceIdentifier\":\"ff5b8ace-8b95-4078-9743-eac1ca5451de\",\"published\":\"2026-05-21T21:16:33.773\",\"lastModified\":\"2026-05-26T17:42:10.967\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Concrete CMS 9.5.0 and below is vulnerable to missing authorization in the bulk_user_assignment.php which can lead to privilege escalation\u00a0to Administrative Group.\u00a0Any authenticated user with access to the bulk user assignment dashboard page can add any user email to any group and can remove legitimate admins.\u00a0The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 7.5 with vector\u00a0CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks\u00a0Vincent55 for reporting.\"}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"ff5b8ace-8b95-4078-9743-eac1ca5451de\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"attackRequirements\":\"PRESENT\",\"privilegesRequired\":\"HIGH\",\"userInteraction\":\"NONE\",\"vulnConfidentialityImpact\":\"HIGH\",\"vulnIntegrityImpact\":\"HIGH\",\"vulnAvailabilityImpact\":\"HIGH\",\"subConfidentialityImpact\":\"NONE\",\"subIntegrityImpact\":\"NONE\",\"subAvailabilityImpact\":\"NONE\",\"exploitMaturity\":\"NOT_DEFINED\",\"confidentialityRequirement\":\"NOT_DEFINED\",\"integrityRequirement\":\"NOT_DEFINED\",\"availabilityRequirement\":\"NOT_DEFINED\",\"modifiedAttackVector\":\"NOT_DEFINED\",\"modifiedAttackComplexity\":\"NOT_DEFINED\",\"modifiedAttackRequirements\":\"NOT_DEFINED\",\"modifiedPrivilegesRequired\":\"NOT_DEFINED\",\"modifiedUserInteraction\":\"NOT_DEFINED\",\"modifiedVulnConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedVulnIntegrityImpact\":\"NOT_DEFINED\",\"modifiedVulnAvailabilityImpact\":\"NOT_DEFINED\",\"modifiedSubConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedSubIntegrityImpact\":\"NOT_DEFINED\",\"modifiedSubAvailabilityImpact\":\"NOT_DEFINED\",\"Safety\":\"NOT_DEFINED\",\"Automatable\":\"NOT_DEFINED\",\"Recovery\":\"NOT_DEFINED\",\"valueDensity\":\"NOT_DEFINED\",\"vulnerabilityResponseEffort\":\"NOT_DEFINED\",\"providerUrgency\":\"NOT_DEFINED\"}}],\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":8.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.8,\"impactScore\":5.9}]},\"weaknesses\":[{\"source\":\"ff5b8ace-8b95-4078-9743-eac1ca5451de\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-863\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*\",\"versionEndIncluding\":\"9.5.0\",\"matchCriteriaId\":\"435732F0-BA4B-4432-97EA-B730EBD44D4D\"}]}]}],\"references\":[{\"url\":\"https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes\",\"source\":\"ff5b8ace-8b95-4078-9743-eac1ca5451de\",\"tags\":[\"Release Notes\"]}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-8350\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-05-22T13:22:41.872694Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-05-22T13:22:46.917Z\"}}], \"cna\": {\"title\": \"Concrete CMS 9.5.0 and below is vulnerable to missing authorization in the bulk_user_assignment.php which can lead to privilege escalation to Administrative Group\", \"source\": {\"defect\": [\"HackerONE\"], \"advisory\": \"https://hackerone.com/reports/3594435\", \"discovery\": \"EXTERNAL\"}, \"credits\": [{\"lang\": \"en\", \"type\": \"finder\", \"value\": \"Vincent55\"}], \"impacts\": [{\"capecId\": \"CAPEC-1\", \"descriptions\": [{\"lang\": \"en\", \"value\": \"CAPEC-1 Accessing Functionality Not Properly Constrained by ACLs\"}]}], \"metrics\": [{\"format\": \"CVSS\", \"cvssV4_0\": {\"Safety\": \"NOT_DEFINED\", \"version\": \"4.0\", \"Recovery\": \"NOT_DEFINED\", \"baseScore\": 7.5, \"Automatable\": \"NOT_DEFINED\", \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"valueDensity\": \"NOT_DEFINED\", \"vectorString\": \"CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N\", \"exploitMaturity\": \"NOT_DEFINED\", \"providerUrgency\": \"NOT_DEFINED\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"PRESENT\", \"privilegesRequired\": \"HIGH\", \"subIntegrityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"HIGH\", \"subAvailabilityImpact\": \"NONE\", \"vulnAvailabilityImpact\": \"HIGH\", \"subConfidentialityImpact\": \"NONE\", \"vulnConfidentialityImpact\": \"HIGH\", \"vulnerabilityResponseEffort\": \"NOT_DEFINED\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}], \"affected\": [{\"repo\": \"https://github.com/concretecms/concretecms\", \"vendor\": \"Concrete CMS\", \"product\": \"Concrete CMS\", \"versions\": [{\"status\": \"affected\", \"version\": \"5.0\", \"versionType\": \"git\", \"lessThanOrEqual\": \"9.5.0\"}], \"collectionURL\": \"https://github.com/concretecms/concretecms\", \"defaultStatus\": \"unaffected\"}], \"references\": [{\"url\": \"https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes\", \"tags\": [\"release-notes\"]}], \"x_generator\": {\"engine\": \"Vulnogram 1.0.2\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"Concrete CMS 9.5.0 and below is vulnerable to missing authorization in the bulk_user_assignment.php which can lead to privilege escalation\\u00a0to Administrative Group.\\u00a0Any authenticated user with access to the bulk user assignment dashboard page can add any user email to any group and can remove legitimate admins.\\u00a0The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 7.5 with vector\\u00a0CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks\\u00a0Vincent55 for reporting.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"\u003cdiv\u003e\u003cbr\u003e\u003c/div\u003e\u003cdiv\u003eConcrete CMS 9.5.0 and below is vulnerable to m\u003cspan\u003eissing authorization in the bulk_user_assignment.php which can lead to privilege escalation\u0026nbsp;\u003c/span\u003eto Administrative Group\u003cspan\u003e.\u0026nbsp;\u003c/span\u003e\u003cspan\u003eAny authenticated user with access to the bulk user assignment dashboard page can add any user email to any group and can remove legitimate admins.\u003c/span\u003e\u0026nbsp;\u003cspan\u003eThe Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 7.5 with vector\u0026nbsp;\u003c/span\u003eCVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N\u003cspan\u003e. Thanks\u0026nbsp;Vincent55 for reporting.\u0026nbsp;\u003c/span\u003e\u003c/div\u003e\", \"base64\": false}]}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-863\", \"description\": \"CWE-863\"}]}], \"providerMetadata\": {\"orgId\": \"ff5b8ace-8b95-4078-9743-eac1ca5451de\", \"shortName\": \"ConcreteCMS\", \"dateUpdated\": \"2026-05-21T20:28:03.032Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-8350\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-05-22T13:22:50.510Z\", \"dateReserved\": \"2026-05-11T16:40:39.812Z\", \"assignerOrgId\": \"ff5b8ace-8b95-4078-9743-eac1ca5451de\", \"datePublished\": \"2026-05-21T20:28:03.032Z\", \"assignerShortName\": \"ConcreteCMS\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.