# DOMPurify: IN_PLACE: node-removing afterSanitize hook leaves detached subtree event handlers armed, causing DOM XSS

Advisory record · `GHSA-p98j-92pf-mc4p`

- **Identifiers:** `GHSA-p98j-92pf-mc4p` · `CVE-2026-109344`
- **State:** Confirmed
- **Severity:** CVSS 5.1 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:** 30 Sept 2026
- **Updated:** 13 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 30 Sept 2026, 15:37 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `dompurify` (npm): affected `>=3.4.13, <3.4.16`; fixed in `3.4.16`

## Machine-written summary

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

> DOMPurify (npm package dompurify) versions 3.4.13 through 3.4.15 can leave event handlers active on subtrees removed by afterSanitize hooks when run in IN_PLACE mode. An attacker who supplies markup to an application that uses IN_PLACE with such a hook can run script in the victim's page (DOM XSS). Upgrade to dompurify 3.4.16, the listed 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

- 5.1 Medium, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N`, from CNA (VulnCheck)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0019, the 8th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 23 Sept 2026, 15:17 UTC: [Published by the maintainers as a GitHub repository advisory](https://github.com/cure53/DOMPurify/security/advisories/GHSA-p98j-92pf-mc4p)
- 31 Oct 2026, 13:33 UTC: First seen by agentprime
- 31 Oct 2026, 13:33 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-p98j-92pf-mc4p)

## Sources

- [GitHub Advisory Database: GHSA-p98j-92pf-mc4p](https://github.com/advisories/GHSA-p98j-92pf-mc4p)
- [OSV: GHSA-p98j-92pf-mc4p](https://osv.dev/vulnerability/GHSA-p98j-92pf-mc4p)
- <https://github.com/cure53/DOMPurify/security/advisories/GHSA-p98j-92pf-mc4p>
- <https://github.com/cure53/DOMPurify/pull/1636>
- <https://github.com/cure53/DOMPurify/commit/b9b9d80f7e401771c2ccaef5f45def7eec8f27d7>
- <https://github.com/cure53/DOMPurify>
- <https://github.com/cure53/DOMPurify/releases/tag/3.4.16>

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-p98j-92pf-mc4p>, 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-p98j-92pf-mc4p/>. Everything for agents: <https://agentprime.io/llms.txt>.