ARIA attribute has an invalid value

Why does it matter?

WCAG 4.1.2 asks that assistive technology gets the right state and value; browsers ignore a value that WAI-ARIA does not define for this attribute, or read it as something else, so people may hear the wrong thing.

Who it affects: Screen reader and keyboard users, who depend on ARIA and focus order being correct to understand and operate the page.

What does Lumtera flag?

An ARIA attribute whose value WAI-ARIA does not define for it, such as aria-expanded="yes".

Check ID aria-invalid-value — use it to filter the content report or with wp lumtera issues --rule.

How do I fix it in WordPress?

Use one of the values the message lists. Most states take only "true" or "false", not "yes", "no", "on" or "open". If a theme or plugin writes the attribute, report it to its developer.

Example

<button aria-expanded="yes">Menu</button>

<button aria-expanded="true">Menu</button>

How do I check the fix?

1. Update the post. The issue disappears from the Lumtera Accessibility sidebar on the next check, and from the site report on the next scan.
2. Press Tab from the top of the page. Focus should move in reading order and never land on something invisible or silent.