GHSA-G8WR-R2V2-VQC6

Vulnerability from github – Published: 2026-08-27 16:53 – Updated: 2026-08-27 16:53
VLAI
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
Show details on source website
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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"
}



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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

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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.