Vulnerability-Lookup

GHSA-45FJ-FVMM-XCC5

Vulnerability from github – Published: 2026-03-04 03:31 – Updated: 2026-03-04 21:36

Summary

Concrete CMS has a stored Cross-site Scripting (XSS) vulnerability

Details

In Concrete CMS below version 9.4.8, a user with permission to edit a page with element Legacy form can perform a stored XSS attack towards high-privilege accounts via the Question field.

The Concrete CMS security team thanks minhnn42, namdi and quanlna2 from VCSLab-Viettel Cyber Security for reporting.

Severity

4.8 (Medium)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "concrete5/concrete5"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "9.4.8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-3240"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-04T21:36:26Z",
    "nvd_published_at": "2026-03-04T03:16:04Z",
    "severity": "MODERATE"
  },
  "details": "In Concrete CMS below version 9.4.8, a\u00a0user with permission to edit a page with element Legacy form can perform a stored XSS attack towards high-privilege accounts via the\u00a0Question field.\u00a0\n\nThe Concrete CMS security team thanks\u00a0minhnn42, namdi and quanlna2 from VCSLab-Viettel Cyber Security for reporting.",
  "id": "GHSA-45fj-fvmm-xcc5",
  "modified": "2026-03-04T21:36:26Z",
  "published": "2026-03-04T03:31:34Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-3240"
    },
    {
      "type": "WEB",
      "url": "https://github.com/concretecms/concretecms/pull/12826"
    },
    {
      "type": "WEB",
      "url": "https://documentation.concretecms.org/9-x/developers/introduction/version-history/948-release-notes"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/concretecms/concretecms"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Concrete CMS has a stored Cross-site Scripting (XSS) vulnerability"
}

CVE-2026-3240 (GCVE-0-2026-3240)

Vulnerability from cvelistv5 – Published: 2026-03-04 02:15 – Updated: 2026-03-04 15:33

Title

Concrete CMS below 9.4.8 is vulnerable to Stored XSS via Legacy form

Summary

In Concrete CMS below version 9.4.8, a user with permission to edit a page with element Legacy form can perform a stored XSS attack towards high-privilege accounts via the Question field. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 4.8 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N Thanks minhnn42, namdi and quanlna2 from VCSLab-Viettel Cyber Security for reporting.

Severity

4.8 (Medium)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-03-04 15:32 UTC

CWE

CWE-79 - Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting')

Assigner

ConcreteCMS mitre root

References

2 references

URL	Tags
https://github.com/concretecms/concretecms/pull/12826
https://documentation.concretecms.org/9-x/develop…

Impacted products

1 product

Vendor	Product	Version
Concrete CMS	Concrete CMS	Affected: 5 , < 9.4.8 (git)

Credits

minhnn42, namdi and quanlna2 from VCSLab-Viettel Cyber Security

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-3240",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-04T15:32:45.974969Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-04T15:33:21.842Z",
          "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": [
            {
              "lessThan": "9.4.8",
              "status": "affected",
              "version": "5",
              "versionType": "git"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "minhnn42, namdi and quanlna2 from VCSLab-Viettel Cyber Security"
        }
      ],
      "descriptions": [
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          "lang": "en",
          "supportingMedia": [
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              "base64": false,
              "type": "text/html",
              "value": "\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003eIn Concrete CMS below version 9.4.8, a\u0026nbsp;\u003c/span\u003e\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003euser with permission to edit a page with element\u003c/span\u003e Legacy form \u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003ecan perform a stored XSS attack towards high-privilege accounts via the\u0026nbsp;\u003c/span\u003eQuestion\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003e field.\u0026nbsp;The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 4.8 with vector\u0026nbsp;CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N Thanks\u0026nbsp;minhnn42, namdi and quanlna2 from VCSLab-Viettel Cyber Security for reporting.\u003c/span\u003e\u003cbr\u003e\u003cbr\u003e"
            }
          ],
          "value": "In Concrete CMS below version 9.4.8, a\u00a0user with permission to edit a page with element Legacy form can perform a stored XSS attack towards high-privilege accounts via the\u00a0Question field.\u00a0The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 4.8 with vector\u00a0CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N Thanks\u00a0minhnn42, namdi and quanlna2 from VCSLab-Viettel Cyber Security for reporting."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-592",
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            {
              "lang": "en",
              "value": "CAPEC-592 Stored XSS"
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        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 4.8,
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            "privilegesRequired": "HIGH",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "LOW",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
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              "lang": "en",
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      "problemTypes": [
        {
          "descriptions": [
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              "cweId": "CWE-79",
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      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-04T02:15:53.400Z",
        "orgId": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
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        }
      ],
      "source": {
        "advisory": "3451114",
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    "cveId": "CVE-2026-3240",
    "datePublished": "2026-03-04T02:15:53.400Z",
    "dateReserved": "2026-02-26T01:42:11.496Z",
    "dateUpdated": "2026-03-04T15:33:21.842Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.