CyanogenMod 7, an AOSP version of Android 2.3.x Gingerbread, was just updated to 7.0.3 Stable. A Stable build differs from that of a Release Candidate or Nightly in that it should be ready for everyday use without any known bugs or issues.
That still leaves unknown bugs as a possibility. In this case the dot-revision contains a bug-fix for an update notification system (which is not vitally important) and a security fix (which is important).
If you're running a version of CM7 it's recommended that you update to 7.0.3 Stable as soon as possible. Updates are available through the CM mirror network and through ROM Manager .
As a side note, 7.0.3 is built on Android 2.3.3. The latest nightlies have been using Android 2.3.4, but might have the security hole in them as well. For the time being, if you're running a CM7 Nightly, rolling back to 7.0.3 Stable is advised.
UPDATE: 7.0.3 seems to have some problems with adding Google Accounts and trying to do almost anything in the Market, but ONLY if you're coming from an Android 2.3.4 Nightly.
The 7.0.3 update is ONLY for people using 7.0.2* stable builds. You'll hose your system if you install it on a nightly from the last week.
If you have these problems, either roll back to your previous backup, or do a full wipe before installing 7.0.3.
Source: CyanogenMod Blog