Vulnerability-Lookup

GHSA-G8WR-R2V2-VQC6

Vulnerability from github – Published: 2026-08-27 16:53 – Updated: 2026-08-27 16:53

Summary

silverstripe/userforms vulnerable to remote code execution via userforms email subject

Details

Impact

The userform email subject field in the CMS is vulnerable to a specially crafted payload being used to run arbitrary code on the server.

Reported by

Jack Wallace from Bastion Security

Severity

8.8 (High)


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

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "silverstripe/userforms"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.4.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "silverstripe/userforms"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "7.0.0"
            },
            {
              "fixed": "7.0.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "silverstripe/userforms"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "7.1.0"
            },
            {
              "fixed": "7.1.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-54721"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-20",
      "CWE-94"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-08-27T16:53:17Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Impact\nThe userform email subject field in the CMS is vulnerable to a specially crafted payload being used to run arbitrary code on the server.\n\n### Reported by\nJack Wallace from Bastion Security",
  "id": "GHSA-g8wr-r2v2-vqc6",
  "modified": "2026-08-27T16:53:18Z",
  "published": "2026-08-27T16:53:17Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/silverstripe/silverstripe-userforms/security/advisories/GHSA-g8wr-r2v2-vqc6"
    },
    {
      "type": "WEB",
      "url": "https://github.com/silverstripe/silverstripe-userforms/pull/1441"
    },
    {
      "type": "WEB",
      "url": "https://github.com/silverstripe/silverstripe-userforms/pull/1442"
    },
    {
      "type": "WEB",
      "url": "https://github.com/silverstripe/silverstripe-userforms/commit/23c069866900c19b499bfa997d1e251e97491702"
    },
    {
      "type": "WEB",
      "url": "https://github.com/silverstripe/silverstripe-userforms/commit/c55494ad7c717b199a3c1663b43a54db5d95604c"
    },
    {
      "type": "WEB",
      "url": "https://github.com/FriendsOfPHP/security-advisories/blob/master/silverstripe/userforms/CVE-2026-54721.yaml"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/silverstripe/silverstripe-userforms"
    },
    {
      "type": "WEB",
      "url": "https://github.com/silverstripe/silverstripe-userforms/releases/tag/6.4.9"
    },
    {
      "type": "WEB",
      "url": "https://github.com/silverstripe/silverstripe-userforms/releases/tag/7.0.7"
    },
    {
      "type": "WEB",
      "url": "https://github.com/silverstripe/silverstripe-userforms/releases/tag/7.1.1"
    },
    {
      "type": "WEB",
      "url": "https://www.silverstripe.org/download/security-releases/cve-2026-54721"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "silverstripe/userforms vulnerable to remote code execution via userforms email subject"
}

CVE-2026-54721 (GCVE-0-2026-54721)

Vulnerability from cvelistv5 – Published: 2026-08-27 16:52 – Updated: 2026-08-28 15:58

Title

Silverstripe UserForms: Remote code execution via userforms email subject

Summary

Silverstripe UserForms provides a visual form builder for the Silverstripe CMS. From 6.0.0 until 6.4.9, 7.0.7, and 7.1.1, the userform email recipient subject field in the CMS accepts a specially crafted payload that can be interpreted as executable server-side code. An authenticated CMS user with permission to configure a UserForms email recipient can use the subject field to run arbitrary code on the server, compromising confidentiality, integrity, and availability. This issue is fixed in versions 6.4.9, 7.0.7, and 7.1.1.

Severity

8.8 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:L/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 2026-08-28 15:45 UTC

CWE

CWE-94 - Improper Control of Generation of Code ('Code Injection')

Assigner

GitHub_M mitre root Scorecard

References

8 references

URL	Tags
https://github.com/silverstripe/silverstripe-user…	x_refsource_CONFIRM
https://github.com/silverstripe/silverstripe-user…	x_refsource_MISC
https://github.com/silverstripe/silverstripe-user…	x_refsource_MISC
https://github.com/silverstripe/silverstripe-user…	x_refsource_MISC
https://github.com/silverstripe/silverstripe-user…	x_refsource_MISC
https://github.com/silverstripe/silverstripe-user…	x_refsource_MISC
https://github.com/silverstripe/silverstripe-user…	x_refsource_MISC
https://github.com/silverstripe/silverstripe-user…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
silverstripe	silverstripe-userforms	Affected: < 6.4.9 Affected: >= 7.0.0, < 7.0.7 Affected: >= 7.1.0, < 7.1.1

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JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-54721",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-28T15:45:52.816811Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-28T15:58:28.067Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "silverstripe-userforms",
          "vendor": "silverstripe",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 6.4.9"
            },
            {
              "status": "affected",
              "version": "\u003e= 7.0.0, \u003c 7.0.7"
            },
            {
              "status": "affected",
              "version": "\u003e= 7.1.0, \u003c 7.1.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Silverstripe UserForms provides a visual form builder for the Silverstripe CMS. From 6.0.0 until 6.4.9, 7.0.7, and 7.1.1, the userform email recipient subject field in the CMS accepts a specially crafted payload that can be interpreted as executable server-side code. An authenticated CMS user with permission to configure a UserForms email recipient can use the subject field to run arbitrary code on the server, compromising confidentiality, integrity, and availability. This issue is fixed in versions 6.4.9, 7.0.7, and 7.1.1."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
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          "descriptions": [
            {
              "cweId": "CWE-94",
              "description": "CWE-94: Improper Control of Generation of Code (\u0027Code Injection\u0027)",
              "lang": "en",
              "type": "CWE"
            }
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      "providerMetadata": {
        "dateUpdated": "2026-08-27T16:52:46.023Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/silverstripe/silverstripe-userforms/security/advisories/GHSA-g8wr-r2v2-vqc6",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/silverstripe/silverstripe-userforms/security/advisories/GHSA-g8wr-r2v2-vqc6"
        },
        {
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          "tags": [
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          "url": "https://github.com/silverstripe/silverstripe-userforms/pull/1441"
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        {
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          "tags": [
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          "url": "https://github.com/silverstripe/silverstripe-userforms/pull/1442"
        },
        {
          "name": "https://github.com/silverstripe/silverstripe-userforms/commit/23c069866900c19b499bfa997d1e251e97491702",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/silverstripe/silverstripe-userforms/commit/23c069866900c19b499bfa997d1e251e97491702"
        },
        {
          "name": "https://github.com/silverstripe/silverstripe-userforms/commit/c55494ad7c717b199a3c1663b43a54db5d95604c",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/silverstripe/silverstripe-userforms/commit/c55494ad7c717b199a3c1663b43a54db5d95604c"
        },
        {
          "name": "https://github.com/silverstripe/silverstripe-userforms/releases/tag/6.4.9",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/silverstripe/silverstripe-userforms/releases/tag/6.4.9"
        },
        {
          "name": "https://github.com/silverstripe/silverstripe-userforms/releases/tag/7.0.7",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/silverstripe/silverstripe-userforms/releases/tag/7.0.7"
        },
        {
          "name": "https://github.com/silverstripe/silverstripe-userforms/releases/tag/7.1.1",
          "tags": [
            "x_refsource_MISC"
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          "url": "https://github.com/silverstripe/silverstripe-userforms/releases/tag/7.1.1"
        }
      ],
      "source": {
        "advisory": "GHSA-g8wr-r2v2-vqc6",
        "discovery": "UNKNOWN"
      },
      "title": "Silverstripe UserForms: Remote code execution via userforms email subject"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-54721",
    "datePublished": "2026-08-27T16:52:46.023Z",
    "dateReserved": "2026-06-15T23:07:33.231Z",
    "dateUpdated": "2026-08-28T15:58:28.067Z",
    "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.

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.
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