We have docker automated build that started to fail recently, reproducing commands locally returns the same error.

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 9ECBEC467F0CEB10

echo 'deb http://downloads-distro.mongodb.org/repo/ubuntu-upstart dist 10gen' | sudo tee /etc/apt/sources.list.d/mongodb.list

sudo apt-get update

Result: 

W: http://downloads-distro.mongodb.org/repo/ubuntu-upstart/dists/dist/Release.gpg: Signature by key 492EAFE8CD016A07919F1D2B9ECBEC467F0CEB10 uses weak digest algorithm (SHA1)
E: Failed to fetch store:/var/lib/apt/lists/partial/downloads-distro.mongodb.org_repo_ubuntu-upstart_dists_dist_10gen_binary-amd64_Packages.gz Hash Sum mismatch
E: Some index files failed to download. They have been ignored, or old ones used instead.