What happens if the target attribute contains invalid characters?

If the target attribute contains invalid characters like ASCII newline, tab, or the <code>< character, it is reset to _blank.

This is a security measure to prevent dangling markup injection attacks, where unclosed attributes could capture unintended text. By resetting to _blank, the browser ensures that the attribute is closed properly, maintaining the security and integrity of the document.

<base target="invalid
characters"> <!-- Resets to _blank -->