Question: I am trying to monitor available updates on a CentOS 7 system. Now I had the impression that `yum updateinfo` gives exactly that, and sometimes it does, but right now on one machine it says

```
Updates Information Summary: updates
    1 Security notice(s)
    3 Bugfix notice(s)
    1 Enhancement notice(s)

```

Which looks as if there are 5 updates available, but actually `yum update` and `yum check-update` report **60** packages that are supposed to be upgraded.

Is `yum check-update` then the only way to find out all possible updateable packages?

Answer: 
**Why does yum updateinfo not show all updates?** It gives different info *by design*.

It looks like you submitted `yum updateinfo summary updates`, which shows advisory information, as is apparent by looking at the output and according to `man yum`:

> 
> **\* updates** Is used to display information about advisories for packages that can be updated. This is the default.
> 
> 
> 

On the other hand, according to its [documentation](https://www.centos.org/docs/5/html/5.1/Deployment_Guide/s1-yum-useful-commands.html), `yum check-update` does this:

> 
> This command allows you to determine whether any updates are available for your installed packages. yum returns a list of all package updates from all repositories if any are available. 
> 
> 
>
According to the following [redhat solution article](https://access.redhat.com/solutions/10021), you can use `updateinfo` in a number of ways to get information on security-related updates. 

**NOTE**: For systems running older versions than RHEL7/CentOS7, the `yum-plugin-security` package (plugin) is required.

Looks like you want is one of the following:

```
yum info-sec

```

Shows available security updates verbosely

```
yum updateinfo list

```

Shows available advisories

```
yum updateinfo RHSA-2018:2285

```

Shows the specific advisory