Vulnerability-Lookup

GHSA-XJG6-5V39-V7FC

Vulnerability from github – Published: 2026-05-26 13:30 – Updated: 2026-05-26 15:32

Details

Concrete CMS 9.5.0 and below is vulnerable to CSRF via Backend\File::approveVersion. Victim with edit_file_contents permission is CSRF'd into publishing an attacker-chosen previously-uploaded version (downgrade to an older version of a file, or activation of a co-editor's unpublished version). The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 2.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Winston Crooker for reporting.

Severity

4.3 (Medium)


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

2.3 (Low)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-8340"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-352"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-22T15:16:26Z",
    "severity": "LOW"
  },
  "details": "Concrete CMS 9.5.0 and below is vulnerable to CSRF via Backend\\File::approveVersion.\u00a0Victim with\u00a0edit_file_contents\u00a0permission is CSRF\u0027d into publishing an attacker-chosen previously-uploaded version (downgrade to an older version of a file, or activation of a co-editor\u0027s unpublished version).\u00a0The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 2.3 with vector\u00a0CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Winston Crooker for reporting.",
  "id": "GHSA-xjg6-5v39-v7fc",
  "modified": "2026-05-26T15:32:09Z",
  "published": "2026-05-26T13:30:17Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-8340"
    },
    {
      "type": "WEB",
      "url": "https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/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",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-8340 (GCVE-0-2026-8340)

Vulnerability from cvelistv5 – Published: 2026-05-22 13:58 – Updated: 2026-05-22 17:26

Title

Concrete CMS 9.5.0 and below is vulnerable to CSRF via Backend\File::approveVersion

Summary

Severity

2.3 (Low)


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

CWE

CWE-352 - Cross-Site request forgery (CSRF)

Assigner

ConcreteCMS

References

1 reference

URL	Tags
https://documentation.concretecms.org/9-x/develop…	release-notes

Impacted products

1 product

Vendor	Product	Version
Concrete CMS	Concrete CMS	Affected: 5.0 , ≤ 9.5.0 (git)

Credits

Winston Crooker

Show details on NVD website

JSON

To clipboard

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                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-22T17:25:35.635711Z",
                "version": "2.0.3"
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          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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          "vendor": "Concrete CMS",
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    "datePublished": "2026-05-22T13:58:55.844Z",
    "dateReserved": "2026-05-11T16:05:50.640Z",
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    "state": "PUBLISHED"
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}

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.

Action not permitted

GHSA-XJG6-5V39-V7FC

CVE-2026-8340 (GCVE-0-2026-8340)

Tags

Sightings

Nomenclature