ApostropheCMS: Incomplete CVE-2026-53606: `meta http-equiv=refresh` `content` still ships `javascript:` / `data:` URLs

{
  "id": "d480664078e6e7289c6c507d02ad965bbc0aa82f056f4ef521c53da73e15cc00",
  "url": "https://osv.dev/vulnerability/GHSA-cv27-6wvh-8x7j",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ApostropheCMS: Incomplete CVE-2026-53606: `meta http-equiv=refresh` `content` still ships `javascript:` / `data:` URLs",
    "summary": "### Summary CVE-2026-53606 expanded `allowedSchemesAppliedToAttributes` so named URL attributes (`action`, `formaction`, `data`, `poster`, `background`, later `ping`, `xlink:href`, …) go through `naughtyHref()`. A **URL nested inside `meta` `content`** (`http-equiv=refresh`) is not an attribute name on that list, so the embedded destination is never scheme-checked. Default `allowedTags` still omit `meta`. Same non-default integrator config as 53606: allow `meta` plus `http-equiv` / `content`. On **2.17.7**: ```text sanitizeHtml( '', { allowedTags: ['meta'], allowedAttributes: { meta: ['http-equiv', 'content'] } } ) // => ``` `data:text/html,…` and arbitrary `https:` destinations also survive. `formaction=\"javascript:…\"` (53606) is stripped. Please **Request CVE**. Credit: Finder + Reporter (`adrbogacz`). ### Details `naughtyHref()` only runs when the attribute name is in `allowedSchemesAppliedToAttributes` (`index.js` ~385). Refresh URLs live in a `content` value of the form `0;url=…`, so the gate never fires. Adding `content` to that list wholesale would break ordinary meta `content` (description, viewport). **Fix:** when `http-equiv` is `refresh` (case-insensitive), parse the `; url=` destination and run `naughtyHref('meta', url)`. Drop `content` (or the tag) if the URL is rejected. Leave other `meta` `content` values alone. ### PoC Local `sanitize-html@2.17.7`. Output inspection only: ```text node -e ' const sanitize = require(\"sanitize-html\"); const opts = { allowedTags: ",
    "evidence": "osv:GHSA-cv27-6wvh-8x7j",
    "products": [
      {
        "name": {
          "value": "sanitize-html",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.18.0",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "GHSA-cv27-6wvh-8x7j",
      "aliases": [
        "CVE-2026-113661",
        "GHSA-cv27-6wvh-8x7j"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2.18.0"
                }
              ]
            }
          ],
          "package": {
            "name": "sanitize-html",
            "purl": "pkg:npm/sanitize-html",
            "ecosystem": "npm"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-cv27-6wvh-8x7j/GHSA-cv27-6wvh-8x7j.json"
          }
        }
      ],
      "modified": "2026-10-20T18:30:03.592709324Z",
      "provider": "osv",
      "references": [
        "https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-cv27-6wvh-8x7j",
        "https://github.com/apostrophecms/apostrophe/commit/9500b8b0e1d630d5e07fbb5fd2c25ed0943845ce",
        "https://github.com/apostrophecms/apostrophe/commit/f84fd41cbf6c22eb8d0008fc9c25df1f7130b350",
        "https://github.com/apostrophecms/apostrophe",
        "https://github.com/apostrophecms/apostrophe/releases/tag/sanitize-html@2.18.0"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-79"
        ],
        "severity": "MODERATE",
        "github_reviewed": true,
        "nvd_published_at": null,
        "github_reviewed_at": "2026-10-20T18:15:33Z"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-113661",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 390148,
  "published_at": "2026-10-20T18:15:33+00:00"
}