This issue has been fixed already for the Mac port in the bug #260469, and the GCrypt implementation of the X25519 algorithm has this checks already. So this bug is about implementing the same check for the GTK+ port.
Pull request: https://github.com/WebKit/WebKit/pull/17583
Committed 267957@main (6940fc8a24d0): <https://commits.webkit.org/267957@main> Reviewed commits have been landed. Closing PR #17583 and removing active labels.
<rdar://problem/115435624>