Incorrect access control in the Forgot Your Password function of EMSigner v2.8.7 allows unauthenticated attackers to access accounts of all registered users, including those with administrator privileges via a crafted password reset token.

Incorrect access control in the AdHoc User creation form of EMSigner v2.8.7 allows unauthenticated attackers to arbitrarily modify usernames and privileges by using the email address of a registered user.

Insecure Direct Object References (IDOR) in EMSigner v2.8.7 allow attackers to gain unauthorized access to application content and view sensitive data of other users via manipulation of the documentID and EncryptedDocumentId parameters.