# DOMPurify: SMIL attributeName=href guard is skipped when PARSER_MEDIA_TYPE is application/xhtml+xml Advisory record · `GHSA-c6gr-qvv4-5v3f` - **Identifiers:** `GHSA-c6gr-qvv4-5v3f` · `CVE-2026-116802` - **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:** 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. > DOMPurify versions before 3.4.17 (fixed in 3.4.17) fail to strip SMIL attributeName values containing "href" when the application uses PARSER_MEDIA_TYPE set to application/xhtml+xml and allows animate or set with attributeName. An attacker who can supply markup to such a sanitizer could keep a payload that, once a user clicks the parent link, runs script in the application's origin, so this is a stored or reflected XSS needing a user click. The issue does not occur with default configurations or in text/html mode. 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:** 0.0022, the 12th percentile, on 10 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days. ## Timeline - 12 Oct 2026, 12:40 UTC: [Published by the maintainers as a GitHub repository advisory](https://github.com/cure53/DOMPurify/security/advisories/GHSA-c6gr-qvv4-5v3f) - 26 Oct 2026, 23:05 UTC: [Confirmed by the CVE List](https://www.cve.org/CVERecord?id=CVE-2026-116802) - 27 Oct 2026, 00:17 UTC: [Confirmed by NVD](https://nvd.nist.gov/vuln/detail/CVE-2026-116802) - 31 Oct 2026, 13:33 UTC: First seen by agentprime - 31 Oct 2026, 13:33 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-c6gr-qvv4-5v3f) ## Sources - [GitHub Advisory Database: GHSA-c6gr-qvv4-5v3f](https://github.com/advisories/GHSA-c6gr-qvv4-5v3f) - [OSV: GHSA-c6gr-qvv4-5v3f](https://osv.dev/vulnerability/GHSA-c6gr-qvv4-5v3f) - - - - - 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 (), 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: - In a browser: reads your lockfile in the browser, never uploading it. - Whether it touches your code, with file and line: the Claude Code plugin, - As JSON: , or `POST https://api.agentprime.io/v1/match` with your packages () --- The web page: . Everything for agents: .