The official images aren't fixed in time, assuming you're pulling using a tag e.g redis:3.0. That image may be updated at any point and should be updated with minor patches and security updates. Rather than manually apply patches, just pull the image again to get the updates. If the image hasn't been updated, complain loudly.
If you want your image to be "fixed in time", pull by digest instead.
If you want your image to be "fixed in time", pull by digest instead.