high · 8.5 Patched

TinyMCE Cross-Site Scripting (XSS) vulnerability using media plugin `data-mce-object` serialization

CVE-2026-116675 · GHSA-mf2p-h6hf-fcwm · published 27 Oct 2026

How serious is it

  • Severity: high, CVSS score 8.5 out of 10.
  • No exploit prediction (EPSS) score yet.
  • Not on the CISA list of exploited vulnerabilities.
  • No public exploit in Exploit-DB.

Is your app affected by CVE-2026-116675?

Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.

Who is affected

  • tinymce (npm) >= 8.5.1, < 8.9.3
  • TinyMCE (NuGet) >= 8.5.1, < 8.9.3
  • tinymce/tinymce (Packagist) >= 8.5.1, < 8.9.3
  • tinymce (npm) = 7.9.3
  • TinyMCE (NuGet) = 7.9.3
  • tinymce/tinymce (Packagist) = 7.9.3

How to check

  1. Run npm ls tinymce in your project to see the installed version, including copies pulled in by other packages.
  2. Look for TinyMCE in your lockfile and compare its version with the range above.
  3. Run composer show tinymce/tinymce in your project to see the installed version, including copies pulled in by other packages.
  4. Or paste your lockfile into the checker: it lists every package with a known vulnerability, this one included.
  5. Or run npx shippable-dev scan localhost:3000 in your project folder. It reads your lockfile and flags this vulnerability along with every other known one.

How to fix

Copies a prompt for Claude Code, Cursor or Codex: it checks your lockfiles for this and upgrades it.
  1. On >= 8.5.1, < 8.9.3: Upgrade tinymce to 8.9.3 or later, commit the lockfile and redeploy.
  2. On >= 8.5.1, < 8.9.3: Upgrade TinyMCE to 8.9.3 or later, commit the lockfile and redeploy.
  3. On >= 8.5.1, < 8.9.3: Upgrade tinymce/tinymce to 8.9.3 or later, commit the lockfile and redeploy.
  4. On = 7.9.3: Upgrade tinymce to 7.9.4 or later, commit the lockfile and redeploy.
  5. On = 7.9.3: Upgrade TinyMCE to 7.9.4 or later, commit the lockfile and redeploy.
  6. On = 7.9.3: Upgrade tinymce/tinymce to 7.9.4 or later, commit the lockfile and redeploy.
  7. If a vulnerable version was live, check your logs and rotate the secrets that server could read.

The advisory

### Impact Stored XSS vulnerability in the media plugin. Attackers can inject malicious scripts via elements crafted through the data-mce-object attribute, which are created and executed before sanitization. Impacts users of TinyMCE with the media plugin enabled. ### Patches This vulnerability has been patched in TinyMCE 8.9.3 and TinyMCE 7.9.4 by ensuring that, when using the media plugin, any content created through the data-mce-object attribute is properly sanitized first. ### Workarounds No official workaround available. ### Fix To avoid this vulnerability: Upgrade to TinyMCE 8.9.3 or higher. Upgrade to TinyMCE 7.9.4 or higher. ### Acknowledgements Tiny thanks [Fariskhi Vidyan](https://github.com/farisv) and David Vieira Kurz (HiSolutions AG) for their help identifying this vulnerability.

Check your whole app

Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.

References

Merged from GitHub Advisory Database, OSV. Last updated 28 Oct 2026. All vulnerabilities · RSS · JSON

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