The CLI in npm before 2.15.1 and 3.x before 3.8.3, as used in Node.js 0.10 before 0.10.44, 0.12 before 0.12.13, 4 before 4.4.2, and 5 before 5.10.0, includes bearer tokens with arbitrary requests, which allows remote HTTP servers to obtain sensitive information by reading Authorization headers.
https://nodejs.org/en/blog/vulnerability/npm-tokens-leak-march-2016/
https://github.com/npm/npm/issues/8380
https://github.com/npm/npm/commit/fea8cc92cee02c720b58f95f14d315507ccad401
https://github.com/npm/npm/commit/f67ecad59e99a03e5aad8e93cd1a086ae087cb29
http://www-01.ibm.com/support/docview.wss?uid=swg21980827
http://blog.npmjs.org/post/142036323955/fixing-a-bearer-token-vulnerability