# DOMPurify IN_PLACE: hook that removes a parent or sibling leaves the detached subtree's event handlers armed (incomplete fix for GHSA-p98j-92pf-mc4p)

Advisory record · `GHSA-mrv2-3pqr-j5jr`

- **Identifiers:** `GHSA-mrv2-3pqr-j5jr` · `CVE-2026-116803`
- **State:** Confirmed
- **Severity:** CVSS 5.1 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-79](https://cwe.mitre.org/data/definitions/79.html) · [CWE-693](https://cwe.mitre.org/data/definitions/693.html)
- **Tags:** [Cross-site scripting (XSS)](https://agentprime.io/advisories/tag/xss.md) · [CWE-693](https://agentprime.io/advisories/tag/cwe-693.md)
- **Published:** 22 Oct 2026
- **Updated:** 27 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 22 Oct 2026, 16:24 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `dompurify` (npm): affected `<3.4.17`; fixed in `3.4.17`

## Machine-written summary

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

> Affected: the npm package dompurify before 3.4.17, with 3.4.17 as the fixed version. In IN_PLACE mode, a hook that removes a node other than the one it was called for (such as the current node's parent or an unvisited sibling) leaves that detached subtree's event handlers active, so an already-loading element like an img with onerror can still fire after sanitize() returns. An attacker who supplies markup to an application that uses such a hook could get DOM XSS; the source frames this as an application choice rather than a default-configuration flaw. Upgrade to dompurify 3.4.17 or later.

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:** 0.0016, the 5th percentile, on 7 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 26 Oct 2026, 23:05 UTC: [Confirmed by the CVE List](https://www.cve.org/CVERecord?id=CVE-2026-116803)
- 31 Oct 2026, 13:33 UTC: First seen by agentprime
- 31 Oct 2026, 13:33 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-mrv2-3pqr-j5jr)

## Sources

- [GitHub Advisory Database: GHSA-mrv2-3pqr-j5jr](https://github.com/advisories/GHSA-mrv2-3pqr-j5jr)
- [OSV: GHSA-mrv2-3pqr-j5jr](https://osv.dev/vulnerability/GHSA-mrv2-3pqr-j5jr)
- <https://github.com/cure53/DOMPurify/security/advisories/GHSA-mrv2-3pqr-j5jr>
- <https://github.com/cure53/DOMPurify/pull/1672>
- <https://github.com/cure53/DOMPurify/commit/a77a3e78b59f72fa4d1c83f22e121ad9cc7d3575>
- <https://github.com/cure53/DOMPurify>
- <https://github.com/cure53/DOMPurify/releases/tag/3.4.17>

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-mrv2-3pqr-j5jr>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

---

The web page: <https://agentprime.io/advisories/GHSA-mrv2-3pqr-j5jr/>. Everything for agents: <https://agentprime.io/llms.txt>.
