The x86info package in the RHEL5 is very very old. It cannot recognize a lot of new important features, such as L3-cache, ssse3, sse4_1, sse4_2, vmx.
The package do not provide a library nor an API, so the rebasement would no break the ABI compliant.
Please rebase that package to the latest version.
This bug/component is not included in scope for RHEL-5.11.0 which is the last RHEL5 minor release. This Bugzilla will soon be CLOSED as WONTFIX (at the end of RHEL5.11 development phase (Apr 22, 2014)). Please contact your account manager or support representative in case you need to escalate this bug.
Thank you for submitting this request for inclusion in Red Hat Enterprise Linux 5. We've carefully evaluated the request, but are unable to include it in RHEL5 stream. If the issue is critical for your business, please provide additional business justification through the appropriate support channels (https://access.redhat.com/site/support).