vertical-align property is removed when saving a Page

pashultz

One of our faculty members is using a table to show his class schedule in Canvas. He would like to vertically align the dates to the top of their cell, so he uses the Cell Properties dialog in the RCE, resulting in code like this:

<td style="width: 15%; vertical-align: top;">

But after he saves the Page, the vertical-align property is stripped:

<td style="width: 15%;">

We found a workaround using the valign attribute, but it requires manually editing the code. As far as I can tell, the HTML Allowlist document says both methods (valign attribute and vertical-align style property) are allowed. Is this a bug?

Thank you!

Jeff_F

@pashultz - You are correct. The HTML is valid, so this appears to be a sanitizer mismatch. The RCE generates vertical-align: top;, and Canvas lists vertical-align as an allowed CSS property, but the server-side sanitizer removes it when the page is saved. Since valign="top" is retained, the sanitizer’s behavior does not appear consistent with the published allowlist. This is likely either a Canvas bug or an undocumented restriction.

I suggest escalating to Instructure Support for clarification and, if confirmed, requesting either a bug fix or an update to the allowlist documentation so that administrators and instructional designers know what behavior to expect.