# ApostropheCMS sanitize-html: nonTextTags discard region ends early on an implied close, letting \<noscript> content render

Advisory record · `GHSA-x3q4-9hxx-gx8m`

- **Identifiers:** `GHSA-x3q4-9hxx-gx8m` · `CVE-2026-113654`
- **State:** Confirmed
- **Severity:** CVSS 5.3 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-79](https://cwe.mitre.org/data/definitions/79.html)
- **Tags:** [Cross-site scripting (XSS)](https://agentprime.io/advisories/tag/xss.md)
- **Published:** 20 Oct 2026
- **Updated:** 20 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 20 Oct 2026, 18:03 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `sanitize-html` (npm): affected `<2.18.0`; fixed in `2.18.0`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> The sanitize-html npm package, versions before 2.18.0, is affected. Its handling of nonTextTags (such as noscript-adjacent content) ends the discard region early when htmlparser2 emits an implied close, so content inside a noscript element can be passed through as ordinary markup. An attacker who can supply HTML to be sanitized can get elements into the output that a browser with scripting enabled would not render, and the source notes this is a parsing mismatch rather than a full exploit chain. The fix is to upgrade to sanitize-html 2.18.0 or later, which is listed as the fixed version.

Written 31 Oct 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 5.3 Medium, CVSS 4.0: `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`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0043, the 37th percentile, on 11 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 13:33 UTC: First seen by agentprime
- 31 Oct 2026, 13:33 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-x3q4-9hxx-gx8m)

## Sources

- [GitHub Advisory Database: GHSA-x3q4-9hxx-gx8m](https://github.com/advisories/GHSA-x3q4-9hxx-gx8m)
- [OSV: GHSA-x3q4-9hxx-gx8m](https://osv.dev/vulnerability/GHSA-x3q4-9hxx-gx8m)
- <https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-x3q4-9hxx-gx8m>
- <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>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-x3q4-9hxx-gx8m>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-x3q4-9hxx-gx8m/>. Everything for agents: <https://agentprime.io/llms.txt>.