{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "plone.restapi"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "9.15.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "plone.restapi"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "10.0.0"
            },
            {
              "fixed": "10.0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "10.0.0"
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-80"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-17T18:36:34Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nA stored XSS affecting RichText fields. RichTextValue.output returns the raw, unsanitized stored value whenever the stored mimeType equals the outputMimeType. Because the safe-HTML output type (`text/x-html-safe`) is the type that signifies \"already sanitized\", any value whose stored mimeType equals it bypasses the safe_html transform entirely on render. The transform itself is sound \u2014 it correctly strips `on*` event-handler attributes and `javascript:/data:` URIs; the defect is that it is never invoked for these values. The unsanitized value is then emitted via `tal:content=\"structure ...\"`, which performs no escaping, so the payload executes in the viewer\u0027s browser. \n\nThis can be a problem when a RichText field is wrongly defined in code with a `mimeType` and `outputMimeType` that are the same, or when the REST API is used to the same effect.\n\nThis is the same vulnerability as reported in `plone.app.textfield`:\nhttps://github.com/plone/plone.app.textfield/security/advisories/GHSA-4r4f-gg25-rmg5\n\n### Patches\nThe problem has been patched:\n\n* For Plone 6.0 and 6.2, upgrade `plone.restapi` to 9.15.6.\n* For Plone 6.2, upgrade `plone.restapi` to 10.0.1.\n\nThis will prevent abusing the REST API to store wrong rich text values.\n\nThis will **not** prevent XSS from rich text fields that already have wrong values.  For that, you will need a patched `plone.app.textfield` version. See the `plone.app.textfield` advisory linked above for versions.\n\n### Workarounds\nThere is no known workaround.",
  "id": "GHSA-8rqh-vxpr-x77p",
  "modified": "2026-07-17T18:36:34Z",
  "published": "2026-07-17T18:36:34Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/plone/plone.app.textfield/security/advisories/GHSA-4r4f-gg25-rmg5"
    },
    {
      "type": "WEB",
      "url": "https://github.com/plone/plone.restapi/security/advisories/GHSA-8rqh-vxpr-x77p"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/plone/plone.restapi"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "plone.restapi: Stored XSS by spoofing mime type"
}