Question about updating pending secret SF-86 Help

I unwillingly and by mistake forgot to disclose something on my SF-86 and realized this recently. It has been a while now since I applied. My gut feeling is i should speak with my FSO. I just have a few questions.

Can I update my SF-86?
If so, do I have to my FSO what it is or can I just say ‘I want to update it’
if i have to tell him, does he have to keep it between him and I if it’s not too serious?

Once the SF-86 application is submitted to OPM via e-QIP there are no more opportunities to update it since the investigation is already underway and items are scheduled based on what you have provided. You can however, provide the FSO or HR rep that initiated your e-QIP the updated information (in writing) and ask them to send it to OPM to include in your investigation. The FSO/HR rep cannot disclose the information to the hiring manager unless it is egregious enough that it would cause immediate termination/removal regardless of whether it was for a clearance or not.

I had to update stuff for my SF-86 too. There is an SF86C that you can fill out in writing and give to your FSO. Scan it and make it a PDF. Depending on what it is and how long ago the SF86 was submitted might not help things. But for worst case, tell your investigator in your interview and provide the written SF86C for them with dates and signatures. I had to do this for employment history and a foreign contact’s information update.