Go before 1.14.8 and 1.15.x before 1.15.1 allows XSS because text/html is the default for CGI/FCGI handlers that lack a Content-Type header.

Go before 1.13.15 and 14.x before 1.14.7 can have an infinite read loop in ReadUvarint and ReadVarint in encoding/binary via invalid inputs.

Go before 1.13.13 and 1.14.x before 1.14.5 has a data race in some net/http servers, as demonstrated by the httputil.ReverseProxy Handler, because it reads a request body and writes a response at the same time.

In Go before 1.13.13 and 1.14.x before 1.14.5, Certificate.Verify may lack a check on the VerifyOptions.KeyUsages EKU requirements (if VerifyOptions.Roots equals nil and the installation is on Windows). Thus, X.509 certificate verification is incomplete.

Go before 1.12.10 and 1.13.x before 1.13.1 allow HTTP Request Smuggling.

net/url in Go before 1.11.13 and 1.12.x before 1.12.8 mishandles malformed hosts in URLs, leading to an authorization bypass in some applications. This is related to a Host field with a suffix appearing in neither Hostname() nor Port(), and is related to a non-numeric port number. For example, an attacker can compose a crafted javascript:// URL that results in a hostname of google.com.

Go through 1.12.5 on Windows mishandles process creation with a nil environment in conjunction with a non-nil token, which allows attackers to obtain sensitive information or gain privileges.

Go through 1.12 on Windows misuses certain LoadLibrary functionality, leading to DLL injection.

Go before 1.10.8 and 1.11.x before 1.11.5 mishandles P-521 and P-384 elliptic curves, which allows attackers to cause a denial of service (CPU consumption) or possibly conduct ECDH private key recovery attacks.