ApostropheCMS sanitize-html: nonTextTags discard region ends early on an implied close, letting content render

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

5.3 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-113654: 0.43% estimated exploitation activity in the next 30 days; percentile 37.53 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary sanitize-html discards the content of every element in nonTextTags. It delimits that region using htmlparser2's close events, and ignores the isImplied flag htmlparser2 passes it. Closing a still-open ancestor from inside a <noscript makes htmlparser2 unwind its stack past the noscript; the synthetic implied close it emits on the way ends the discard region early, and everything after it is treated as ordinary body content. A browser with scripting enabled parses <noscript content as raw text, so the same markup renders as inert text there. The sanitizer therefore emits elements the page itself would not have. Reproduction Chrome, given the same input, renders no <img — the whole payload is raw text inside the unclosed <noscript. Verified with Playwright, srcdoc into an iframe so the scripting flag is on. A <![CDATA[ variant hides the opening tag from the parser entirely and has the same effect: htmlparser2 runs a CDATA token to ]]; Chrome ends a bogus comment at the first ,…

Published by the source

20 Oct 2026, 18:03 UTC

Last modified by the source

20 Oct 2026, 18:15 UTC

Source last checked

26 Oct 2026, 13:07 UTC

1. Revision 4 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-x3q4-9hxx-gx8m

2. Revision 3 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-x3q4-9hxx-gx8m

4. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-x3q4-9hxx-gx8m

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# Patch Next advisory brief: CVE-2026-113654

Advisory: ApostropheCMS sanitize-html: nonTextTags discard region ends early on an implied close, letting content render
IDs: CVE-2026-113654, GHSA-x3q4-9hxx-gx8m
Record: https://patchnext.com/advisories/cve-2026-113654 (revision 4, source checked 26 Oct 2026, 13:07 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: sanitize-html 2.18.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm sanitize-html: affected < 2.18.0; fixed in 2.18.0

## Suggested inspection (read-only)
- `npm ls sanitize-html --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on sanitize-html.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-x3q4-9hxx-gx8m (GitHub-reviewed advisory GHSA-x3q4-9hxx-gx8m lists affected ranges: npm sanitize-html >=0 <2.18.0)
- Verified: https://osv.dev/vulnerability/GHSA-x3q4-9hxx-gx8m (OSV record GHSA-x3q4-9hxx-gx8m lists affected ranges: npm sanitize-html >=0 <2.18.0 (fixed))

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