Forbearance on student loan

I applied for a secret security clearance but was not aware that one of my loans was delinquent for 180 days. The loan is for $4,000 and is currently in forbearance. The lender and I have been in constant communication and I am currently in good standing with them. However because I was unaware of the negative remarks on my credit report I did not report it on the application for security clearance. I have other loans and all have been paid on time. This is the only negative on my credit report. Will I be denied my security clearance even though I have been granted forbearance?

No, the fact that you have been addressing the debt with the creditor shows a good faith effort and appears to be an isolated occurrence. Not listing it is actually more serious and if your explanation can be verified then it is also not an issue.