Go before 1.12.16 and 1.13.x before 1.13.7 (and the crypto/cryptobyte package before 0.0.0-20200124225646-8b5121be2f68 for Go) allows attacks on clients (resulting in a panic) via a malformed X.509 certificate.
https://www.oracle.com/security-alerts/cpuApr2021.html
https://www.debian.org/security/2021/dsa-4848
https://security.netapp.com/advisory/ntap-20200327-0001/
https://groups.google.com/forum/#%21topic/golang-announce/Hsw4mHYc470
https://groups.google.com/forum/#%21topic/golang-announce/-sdUB4VEQkA