CVE-2017-1000400
The Jenkins 2.73.1 and earlier, 2.83 and earlier remote API at /job/(job-name)/api contained information about upstream and downstream projects. This included information about tasks that the current user otherwise has no access to, e.g. due to lack of Item/Read permission. This has been fixed, and the API now only lists upstream and downstream projects that the current user has access to.
Versions it affects
Software versions checked with the free lookup that CVE-2017-1000400 applies to, and the release that fixes it where the sources name one.
Is this running somewhere in your estate?
The Vulnerability Reporter inventories every machine and tells you when an advisory like this one applies to you.