curl 7.63.0 to and including 7.75.0 includes vulnerability that allows a malicious HTTPS proxy to MITM a connection due to bad handling of TLS 1.3 session tickets. When using a HTTPS proxy and TLS 1.3, libcurl can confuse session tickets arriving from the HTTPS proxy but work as if they arrived from the remote server and then wrongly "short-cut" the host handshake. When confusing the tickets, a HTTPS proxy can trick libcurl to use the wrong session ticket resume for the host and thereby circumvent the server TLS certificate check and make a MITM attack to be possible to perform unnoticed. Note that such a malicious HTTPS proxy needs to provide a certificate that curl will accept for the MITMed server for an attack to work - unless curl has been told to ignore the server certificate check.
https://www.oracle.com//security-alerts/cpujul2021.html
https://security.netapp.com/advisory/ntap-20210521-0007/
https://security.gentoo.org/glsa/202105-36
https://hackerone.com/reports/1129529
https://curl.se/docs/CVE-2021-22890.html
https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf