---
schema_version: "secwatch.filing_event.v1"
accession: "0001350593-23-000054"
form_type: "8-K"
ticker: "MWA"
cik: "0001350593"
company_name: "Mueller Water Products, Inc."
filed_at: "2023-11-29T23:59:59+00:00"
generated_at: "2026-06-07T20:14:22.804774+00:00"
event_type: "cyber"
sentiment: "negative"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Mueller Water Products reports ransomware attack, delays 10-K filing to Dec 14

## Summary
- Unauthorized access and ransomware deployed on internal systems; incident now contained.
- Disruptions to business applications limited order-taking and shipping; facilities now operational.
- Annual Report on Form 10-K for FY ended Sept 30, 2023 will be delayed; expects filing by Dec 14, 2023.
- Separate minor incident involved an end-of-life system already being replaced.
- Investigation and remediation ongoing, including analysis of accessed or exfiltrated data.

## SEC filing metadata
- accession: 0001350593-23-000054
- form_type: 8-K
- ticker: MWA
- cik: 0001350593
- company_name: Mueller Water Products, Inc.
- filed_at: 2023-11-29T23:59:59+00:00
- event_type: cyber
- sentiment: negative
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1350593/000135059323000054/0001350593-23-000054-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1350593/000135059323000054/mwa-20231129.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001350593-23-000054
- JSON: https://secwatch.observer/filing/0001350593-23-000054.json
- Plain text: https://secwatch.observer/filing/0001350593-23-000054.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.