CSS records are statutorily protected from disclosure pursuant to Family Code § 17212. Per Family Code § 17212(b)(1):

Except as provided in Subdivision (c), all files, applications, papers, documents, and records established or maintained by any public entity pursuant to the administration and administration and implementation of the child and spousal support enforcement program...shall be confidential, shall not be open to examination or released for disclosure for any purpose not directly connected with the administration of the child and spousal support enforcement program. No public entity shall disclose any file, application, paper, document, or record or the information contained theirin, except as expressly authorized by this section.
Family Code §17212(c)(6) provides for the release of information only after a noticed motion and finding that release or disclosure is required by due process.

Personal information is redacted from documents filed with the court:

The confidentiality laws also require CSS to redact address and other personal information from documents that it files with the court, such as income and expense declarations, payroll documents and proofs of service.

Family Code §17212 allows CSS to release the following information from its files without a noticed motion:

  1. A document requested by the party who wrote, prepared or furnished the document to CSS.
  2. A payment history
  3. Income and Expense declaration of either parent for the purpose of establishing or modifying a support order, redacted of all personal identifying information including place of employment, address and social security number.
  4. Upon request by a party that was served, CSS shall release to that person the address where service was accomplished.
  5. Information indicating the existence or imminent threat of a crime against a child may be disclosed to the appropriate law enforcement agency.