I'm using a docker image that comes with Debian 8 (jessie). I'm trying to upgrade curl package to the latest (7.58) from 7.38.
Running apt-cache showpkg curl
shows that 7.38 is the latest version, but curl is at 7.58 (http://www.linuxfromscratch.org/blfs/view/8.2/basicnet/curl.html)
I also checked Debian package website and it it looks like 7.38 is the latest. https://packages.debian.org/jessie/curl
Is there a way to upgrade curl 7.38 on my system to the latest?
This is normal as Debian 8 (jessie) is currently the oldstable release. If you search for Package curl you'll notice that the stable version currently has curl 7.52, while testing & unstable are already on version 7.62.
Old Debian releases won't have new feature updates, but receives security updated for a rather long LTS period. Therefore, having an older version doesn't mean you are at risk. Consider upgrading only if you actually need some new features.