Extremely large RSA keys in certificate chains can cause a client/server to expend significant CPU time verifying signatures. With fix, the size of RSA keys transmitted during handshakes is restricted to <= 8192 bits. Based on a survey of publicly trusted RSA keys, there are currently only three certificates in circulation with keys larger than this, and all three appear to be test certificates that are not actively deployed. It is possible there are larger keys in use in private PKIs, but we target the web PKI, so causing breakage here in the interests of increasing the default safety of users of crypto/tls seems reasonable.

Golang Go is vulnerable to cross-site scripting, caused by improper validation of user-supplied input by the html/template package. A remote attacker could exploit this vulnerability using a specially crafted URL to execute script in a victim's Web browser within the security context of the hosting Web site, once the URL is clicked. An attacker could use this vulnerability to steal the victim's cookie-based authentication credentials.

Golang Go is vulnerable to cross-site scripting, caused by improper validation of user-supplied input by the html/template package. A remote attacker could exploit this vulnerability using a specially crafted URL to execute script in a victim's Web browser within the security context of the hosting Web site, once the URL is clicked. An attacker could use this vulnerability to steal the victim's cookie-based authentication credentials.

A flaw was found in net/http/httputil golang package. When httputil.ReverseProxy.ServeHTTP is called with a Request.Header map containing a nil value for the X-Forwarded-For header, ReverseProxy could set the client IP incorrectly. This issue may affect confidentiality.

In the urllib3 library through 1.24.1 for Python CRLF injection is possible if the attacker controls the request parameter.