Bandwidth Inc.'s Form 10-K Item 1C cybersecurity disclosure describes its enterprise information-security program, governance, vendor-risk management, and ISO/IEC 27001 / SOC 2 Type II certifications. The filing references a single specific incident: a DDoS attack experienced in late 2021 that had a material impact on results of operations. No affected-individual count, data types, threat actor, or financial-impact figure is disclosed within this Item 1C narrative.