Html/Template

If a trusted template author were to write a <script> tag containing an empty 'type' attribute or a 'type' attribute with an ASCII whitespace, the execution of the template would incorrectly escape any data passed into the <script> block.

Published: 2026-05-07T19:41:19.138Z
Updated: 2026-05-08T14:05:05.849Z

CVE-2026-27142 fixed a vulnerability in which URLs were not correctly escaped inside of a <meta> tag's <content> attribute. If the URL content were to insert ASCII whitespaces around the '=' rune inside of the <content> attribute, the escaper would fail to similarly escape it, leading to XSS.

Published: 2026-05-07T19:41:19.524Z
Updated: 2026-05-08T14:05:55.152Z

Context was not properly tracked across template branches for JS template literals, leading to possibly incorrect escaping of content when branches were used. Additionally template actions within JS template literals did not properly track the brace depth, leading to incorrect escaping being applied. These issues could cause actions within JS template literals to be incorrectly or improperly escaped, leading to XSS vulnerabilities.

Published: 2026-04-08T01:06:56.297Z
Updated: 2026-04-13T18:20:46.377Z

Actions which insert URLs into the content attribute of HTML meta tags are not escaped. This can allow XSS if the meta tag also has an http-equiv attribute with the value "refresh". A new GODEBUG setting has been added, htmlmetacontenturlescape, which can be used to disable escaping URLs in actions in the meta content attribute which follow "url=" by setting htmlmetacontenturlescape=0.

Published: 2026-03-06T21:28:14.674Z
Updated: 2026-03-16T15:21:14.465Z

If errors returned from MarshalJSON methods contain user controlled data, they may be used to break the contextual auto-escaping behavior of the html/template package, allowing for subsequent actions to inject unexpected content into templates.

Published: 2024-03-05T22:22:33.640Z
Updated: 2025-03-14T00:55:26.398Z