HighGHSA-mh5m-5hw4-5c69CVE-2026-47760

TinyMCE Cross-Site Scripting (XSS) vulnerability using sanitization bypass through nested SVGs

Published 5 Jun 2026 · Updated 10 Sept 2026

Affected packages

tinymcenpm

Affected: >=6.8.0 <7.1.0
Fixed in: 7.1.0

Update to the fixed version for your release line, for example:npm install tinymce@7.1.0

tinymce/tinymceComposer

Affected: >=6.8.0 <7.1.0
Fixed in: 7.1.0

Update to the fixed version for your release line, for example:composer require tinymce/tinymce:^7.1.0

Details

Impact

TinyMCE 6.8.x contains an XSS vulnerability caused by improper SVG namespace scope handling in the sanitizer. A crafted payload using nested <svg> elements can bypass attribute sanitization and execute arbitrary JavaScript.

Patches

This issue affects TinyMCE 6.8.x-7.0.x. The vulnerability is fixed in TinyMCE 7.1.0 and later.

Workarounds

No official workaround available.

Acknowledgements

Tiny thanks maple3142 (<https://maple3142.net>) of DEVCORE for their help identifying this vulnerability.

References

Fix introduced in TinyMCE 7.1.0 though a rewrite of code causing the vulnerability.

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References

Advisory data from OSV.dev (opens OSV.dev in a new tab), refreshed daily.