It cannot be a coincidence that as soon as the fix for
JDK-8241078 OOM error parsing HTML with large <pre> Tag text
was pushed that the JCK test
javax_swing/text/DefaultStyledDocument/ElementSpec/ESpecCtor.html started to fail on all platforms with the message
ElementSpec2004: Failed. Wrong ElementSpec object

Since this is a JCK failure, I suggest immediate backout of that fix
and later reconsider how else to fix it.