{"id":"CVE-2026-113654","aliases":["GHSA-x3q4-9hxx-gx8m"],"url":"https://o3.security/vulnerability/CVE-2026-113654","summary":"ApostropheCMS sanitize-html: nonTextTags discard region ends early on an implied close, letting <noscript> content render","details":"## Summary\n\n`sanitize-html` discards the *content* of every element in `nonTextTags`. It delimits that region\nusing htmlparser2's close events, and ignores the `isImplied` flag htmlparser2 passes it. Closing a\nstill-open **ancestor** from inside a `<noscript>` makes htmlparser2 unwind its stack past the\n`noscript`; the synthetic implied close it emits on the way ends the discard region early, and\neverything after it is treated as ordinary body content.\n\nA browser with scripting enabled parses `<noscript>` content as **raw text**, so the same markup\nrenders as inert text there. The sanitizer therefore emits elements the page itself would not have.\n\n## Reproduction\n\n```js\nconst sanitizeHtml = require(\"sanitize-html\");\n\nsanitizeHtml('<div><noscript></div><img src=\"http://evil.test/t.gif\"></noscript>', {\n  allowedTags: [\"div\", \"img\"],\n  allowedAttributes: { img: [\"src\"] },\n  nonTextTags: [\"script\", \"style\", \"textarea\", \"option\", \"noscript\"],\n});\n// => '<div></div><img src=\"http://evil.test/t.gif\" />'\n```\n\nChrome, given the same input, renders **no** `<img>` — the whole payload is raw text inside the\nunclosed `<noscript>`. Verified with Playwright, `srcdoc` into an iframe so the scripting flag is on.\n\nA `<![CDATA[` variant hides the opening tag from the parser entirely and has the same effect:\n\n```\n<p>Hi</p><![CDATA[ x > <noscript>]]><a href=\"…\">Reset your password</a><img src=\"…beacon.gif\"></noscript>\n```\n\nhtmlparser2 runs a CDATA token to `]]>`; Chrome ends a bogus comment at the first `>`, so the\n`<noscript>` after it is real to the browser and invisible to the parser.\n\n## Where the behaviour is\n\n`index.js`:\n\n- `:154` — `nonTextTagsArray` (the default list, `['script','style','textarea','option','xmp']`).\n- `:638` — `onclosetag: function (name, isImplied)` — receives the flag.\n- `:644` — `skipTextDepth--` — decrements without consulting `isImplied`.\n\n## Suggested fix\n\nDo not end a discard region on an implied close. htmlparser2 already distinguishes them; the flag\nis passed and discarded. Something close to:\n\n```js\nonclosetag: function (name, isImplied) {\n  if (skipText) {\n    if (isImplied) return;   // an implied close must not end the region\n    skipTextDepth--;\n    …\n```","published":"2026-10-20T16:35:55.161Z","modified":"2026-10-24T02:48:45.073477942Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"npm","name":"sanitize-html","fixedVersion":"2.18.0"}],"fix":{"url":"https://github.com/apostrophecms/apostrophe/commit/9500b8b0e1d630d5e07fbb5fd2c25ed0943845ce","label":"apostrophecms/apostrophe@9500b8b"},"references":[{"type":"WEB","url":"https://github.com/apostrophecms/apostrophe/releases/tag/sanitize-html@2.18.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/113xxx/CVE-2026-113654.json"},{"type":"ADVISORY","url":"https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-x3q4-9hxx-gx8m"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-113654"},{"type":"FIX","url":"https://github.com/apostrophecms/apostrophe/commit/9500b8b0e1d630d5e07fbb5fd2c25ed0943845ce"},{"type":"FIX","url":"https://github.com/apostrophecms/apostrophe/commit/f84fd41cbf6c22eb8d0008fc9c25df1f7130b350"},{"type":"PACKAGE","url":"https://github.com/apostrophecms/apostrophe"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-24T02:48:45.073477942Z"}}