SUSE has issued an advisory today (June 20): http://lists.suse.com/pipermail/sle-security-updates/2018-June/004209.html I think this is the corresponding upstream issue: https://github.com/NagiosEnterprises/nrpe/issues/30 So it looks like it was fixed in 2.16.
nrpe 2.16 seems to have never been released, and I can't find the relevant commits in the git repository (way too much noise). None of the publicly available PR have been merged, in favor of a mysteriouse "complete and backward-compatible" (but unavailable) solution. So, unless an easy solution is found, this is likely to result in a "won't fix" status.
Based on the date of the upstream guy's comment, he might have made a typo and this might have been fixed in 2.15. I'm fine if you want to close this.
No available solution in sight, closing.
Resolution: (none) => WONTFIXStatus: NEW => RESOLVED