# TinyMCE Cross-Site Scripting (XSS) vulnerability using through data-mce- prefixed src, href, style attributes

Advisory record · `GHSA-q742-qvgc-gc2f`

- **Identifiers:** `GHSA-q742-qvgc-gc2f` · `CVE-2026-47759` · `PKSA-rf1b-835f-6yyv`
- **State:** Confirmed
- **Severity:** CVSS 8.7 High
- **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:** 5 Jun 2026
- **Updated:** 10 Sept 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 5 Jun 2026, 20:27 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `tinymce` (npm): affected `<=5.10.9 || >=6.0.0, <7.9.3 || >=8.0.0, <8.5.1`; fixed in `7.9.3`, `8.5.1`
- `TinyMCE` (NuGet): affected `<=5.10.9 || >=6.0.0, <7.9.3 || >=8.0.0, <8.5.1`; fixed in `7.9.3`, `8.5.1`
- `tinymce/tinymce` (Packagist): affected `<=5.10.9 || >=6.0.0, <7.9.3 || >=8.0.0, <8.5.1`; fixed in `7.9.3`, `8.5.1`

## 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

- 8.7 High, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0028, the 20th percentile, on 8 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the GitHub Advisory Database, published 5 Jun 2026. New records show when each source confirmed them.

## Sources

- [GitHub Advisory Database: GHSA-q742-qvgc-gc2f](https://github.com/advisories/GHSA-q742-qvgc-gc2f)
- [OSV: GHSA-q742-qvgc-gc2f](https://osv.dev/vulnerability/GHSA-q742-qvgc-gc2f)
- <https://github.com/tinymce/tinymce/security/advisories/GHSA-q742-qvgc-gc2f>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-47759>
- <https://github.com/tinymce/tinymce>
- <https://www.tiny.cloud/docs/tinymce/7/7.9.3-release-notes/#overview>
- <https://www.tiny.cloud/docs/tinymce/8/8.5.1-release-notes/#overview>

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-q742-qvgc-gc2f>, 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-q742-qvgc-gc2f/>. Everything for agents: <https://agentprime.io/llms.txt>.