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.

The crypto/x509 package of Go before 1.10.6 and 1.11.x before 1.11.3 does not limit the amount of work performed for each chain verification, which might allow attackers to craft pathological inputs leading to a CPU denial of service. Go TLS servers accepting client certificates and TLS clients are affected.

In Go before 1.10.6 and 1.11.x before 1.11.3, the "go get" command is vulnerable to directory traversal when executed with the import path of a malicious Go package which contains curly braces (both '{' and '}' characters). Specifically, it is only vulnerable in GOPATH mode, but not in module mode (the distinction is documented at https://golang.org/cmd/go/#hdr-Module_aware_go_get). The attacker can cause an arbitrary filesystem write, which can lead to code execution.

In Go before 1.10.6 and 1.11.x before 1.11.3, the "go get" command is vulnerable to remote code execution when executed with the -u flag and the import path of a malicious Go package, or a package that imports it directly or indirectly. Specifically, it is only vulnerable in GOPATH mode, but not in module mode (the distinction is documented at https://golang.org/cmd/go/#hdr-Module_aware_go_get). Using custom domains, it's possible to arrange things so that a Git repository is cloned to a folder named ".git" by using a vanity import path that ends with "/.git". If the Git repository root contains a "HEAD" file, a "config" file, an "objects" directory, a "refs" directory, with some work to ensure the proper ordering of operations, "go get -u" can be tricked into considering the parent directory as a repository root, and running Git commands on it. That will use the "config" file in the original Git repository root for its configuration, and if that config file contains malicious commands, they will execute on the system running "go get -u".