The serializer in html5lib before 0.99999999 might allow remote attackers to conduct cross-site scripting (XSS) attacks by leveraging mishandling of the < (less than) character in attribute values.
{
"extracted_events": [
{
"introduced": "0"
},
{
"last_affected": "0.99999999"
}
],
"source": [
"CPE_RANGE",
"REFERENCES"
],
"cpe": "cpe:2.3:a:html5lib:html5lib:*:1.0b8:*:*:*:*:*:*"
}