Is this a CLM (career limiting move)?

Privately bring the error to your superior's attention, and then step back into the shadows. If you have ideas for mitigating, or correcting the error, outline them to your boss. I would expect that your boss will immediately bring the matter to the attention of his superior. Your superiors should have time to take corrective measures, or prepare to deal with any fallout that might come from the error. Far from hurting your career, this should help it. You will have shown attention to detail, and willingness to work within the system. Your loyalty will be appreciated, your credit will rise, and if your suggestions for handling the problem are adopted you will probably not be publically acknowledged, but you will be remembered and owed.

On the other hand, boss's boss may realize there's one too many people on the payroll that knows how dumb he can be.

To be honest Asherman - there is no fallout. It is really a small error and one that has no impact to the client. It is essentially cosmetic and does not affect the "meat" of the report. Basically a subtotal was not included where we typically show a subtotal. The figures all calculate correctly so there really is no "fallout".

Exactly Roger! Actually my boss' boss is a very a nice and a smart guy to boot. It was simply an oversight/basic human error that anyone could make. I have probably made similar errors myself.

You could mention, in passing, to your supervisor that a sub-total right there would have been good.
Can't hurt if they notice you have "attention to detail" and it gets you on their radar screen as a dependable employee. You never know, you might be called-on in the future to proof-read such reports before they go off for final print.

With your clarification........ Forget about it. There are more important fish to fry. Everyone makes little misteps, so be as forgiving to them as you hope they would be for you.

Focus on the big issues, see the big picture. Juniors are generally well advised to maintain a silent complaiance with seniors, unless there is a major problem.

Actually Heeven proofreading/reviewing the numbers on these reports is a good portion of my job. My boss and my boss' boss (in the same capacity) also do this as part of their job. They just do less in number as they of course have higher responsibilities in addition.

That's what I figure too Asherman. I understand as I am sure some one reporting to me may have found a minor misprint as a result of something I overlooked. The important thing is that the report for all intensive purposes is correct. Besides I like the guy.

I have also recently found an error (in this case major) on a peer's report after sending to the client. That was difficult enough to bring up to the higher ups. Fortunately the report had just been sent so it had not gotten into too many hands. We were able to correct the chart and resubmit without much in the way of consequences. Just so you all don't think I am being a brown nose checking other people's reports…the reason I caught these is I am using some information from these reports to incorporate into other information I need for some legal documents.