Can I install glibc from some repo?
Not likely: distributions usually don’t ever update the major/minor version of glibc from the one they originally shipped with, because the likelihood of breaking applications is too great.
You may have to build glibc-2.15, or better current glibc-2.24 from source and install it into non-default location. See this answer.
solved Install glibc 2.15 in Red Hat 6.5 [duplicate]