golang.org/x/net before v0.0.0-20210520170846-37e1c6afe023 allows attackers to cause a denial of service (infinite loop) via crafted ParseFragment input.
https://groups.google.com/g/golang-announce/c/wPunbCPkWUg
https://github.com/golang/net/commit/37e1c6afe02340126705deced573a85ab75209d7