Rust Security Response Working Group reports:
The search feature of mdBook (introduced in version 0.1.4) was
affected by a cross site scripting vulnerability that allowed an
attacker to execute arbitrary JavaScript code on an user's browser
by tricking the user into typing a malicious search query, or
tricking the user into clicking a link to the search page with the
malicious search query prefilled.
mdBook 0.4.5 fixes the vulnerability by properly escaping the search
query.