{"id":"CVE-2026-113661","aliases":["GHSA-cv27-6wvh-8x7j"],"title":"ApostropheCMS: Incomplete CVE-2026-53606: `meta http-equiv=refresh` `content` still ships `javascript:` / `data:` URLs","summary":"ApostropheCMS: Incomplete CVE-2026-53606: `meta http-equiv=refresh` `content` still ships `javascript:` / `data:` URLs","severity":"medium","cvss":5.4,"cwe":["CWE-79"],"vendor":"sanitize-html","product":"sanitize-html","ecosystem":"npm","affected":["sanitize-html < 2.18.0"],"patched":["sanitize-html 2.18.0"],"published":"2026-10-20","updated":"2026-10-20","sourceUpdated":"2026-10-20T18:15:34Z","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-cv27-6wvh-8x7j","references":[{"url":"https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-cv27-6wvh-8x7j"},{"url":"https://github.com/apostrophecms/apostrophe/commit/9500b8b0e1d630d5e07fbb5fd2c25ed0943845ce"},{"url":"https://github.com/apostrophecms/apostrophe/commit/f84fd41cbf6c22eb8d0008fc9c25df1f7130b350"},{"url":"https://github.com/apostrophecms/apostrophe/releases/tag/sanitize-html@2.18.0"},{"url":"https://github.com/advisories/GHSA-cv27-6wvh-8x7j"}],"tags":["ghsa","npm","cve.org"],"ingestedAt":"2026-10-20T18:14:37.222Z","slug":"CVE-2026-113661","body":"## Overview\n\n### Summary\n\nCVE-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.\n\nDefault `allowedTags` still omit `meta`. Same non-default integrator config as 53606: allow `meta` plus `http-equiv` / `content`.\n\nOn **2.17.7**:\n\n```text\nsanitizeHtml(\n  '<meta http-equiv=\"refresh\" content=\"0;url=javascript:alert(1)\">',\n  { allowedTags: ['meta'], allowedAttributes: { meta: ['http-equiv', 'content'] } }\n)\n// => <meta http-equiv=\"refresh\" content=\"0;url=javascript:alert(1)\" />\n```\n\n`data:text/html,…` and arbitrary `https:` destinations also survive. `formaction=\"javascript:…\"` (53606) is stripped.\n\nPlease **Request CVE**. Credit: Finder + Reporter (`adrbogacz`).\n\n### Details\n\n`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).\n\n**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.\n\n### PoC\n\nLocal `sanitize-html@2.17.7`. Output inspection only:\n\n```text\nnode -e '\nconst sanitize = require(\"sanitize-html\");\nconst opts = { allowedTags: [\"meta\"], allowedAttributes: { meta: [\"http-equiv\", \"content\"] } };\nfor (const html of [\n  \"<meta http-equiv=\\\"refresh\\\" content=\\\"0;url=javascript:alert(1)\\\">\",\n  \"<meta http-equiv=\\\"refresh\\\" content=\\\"0;url=data:text/html,aaa\\\">\",\n  \"<form><button formaction=\\\"javascript:alert(1)\\\">x</button></form>\",\n]) {\n  console.log(html, \"=>\", sanitize(html, html.includes(\"meta\") ? opts : { allowedTags: [\"form\",\"button\"], allowedAttributes: { button: [\"formaction\"] } }));\n}\n'\n```\n\nExpected: refresh `javascript:` / `data:` remain; 53606 `formaction` is removed. Do not attach a browser hang or stored-XSS page.\n\n### Impact\n\nAn integrator who allowed `meta` + `content` expecting `allowedSchemes` to apply (the 53606 configuration pattern) still emits a refresh to `javascript:`, `data:`, or an attacker `https:` URL. Stored XSS / open redirect for viewers of that HTML. Default config is not affected.\n\n## Affected packages\n\n- `sanitize-html < 2.18.0`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `sanitize-html 2.18.0`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":29.7,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}