The new vulnerability that Muthiyah spotted was similar to the one he reported in July and allowed anyone to hack Instagram accounts without consent permission.
Facebook has now fixed the vulnerability that Muthiyah reported.
"Facebook and Instagram security team fixed the issue and rewarded me $10000 as a part of their bounty programme," Muthiyah said in a blog post.
Muthiyah found that the same device ID - the unique identifier used by Instagram server to validate password reset codes - can be used to request multiple pass codes of different users.
He showed that this vulnerability can be exploited to hack Instagram accounts.
"You identified insufficient protections on a recovery endpoint, allowing an attacker to generate numerous valid nonces to ten attempt recovery," Facebook said in a letter to Muthiyah.