An authentication bypass vulnerability exists libcurl <8.0.0 in the connection reuse feature which can reuse previously established connections with incorrect user permissions due to a failure to check for changes in the CURLOPTGSSAPIDELEGATION option. This vulnerability affects krb5/kerberos/negotiate/GSSAPI transfers and could potentially result in unauthorized access to sensitive information. The safest option is to not reuse connections if the CURLOPTGSSAPIDELEGATION option has been changed.