SEC 8-K Item 1.05 cybersecurity incident filings, October 2026
Quick answer, Nov 11, 2026Between 1 and 29 October 2026, cut at 12:00 ET on 29 October, one Form 8-K filing reported a material cybersecurity incident under Item 1.05: Park Dental Partners, filed 13 October 2026. Quest Diagnostics disclosed a cybersecurity matter under Item 8.01 on 22 October. Filings on 30 and 31 October are not in this edition.
October 2026 edition. EDGAR filing dates 1 October 2026 to 29 October 2026, cut off at 12:00 ET on 29 October 2026. This edition is frozen at that cut; any correction is added as a dated line. Every edition and the method are on SEC 8-K Item 1.05 cybersecurity incident filings, by month.
Revised 11 November 2026: method section added and findings restated. The Item 8.01 line no longer states a total.
Findings
- Between 1 October and 29 October 2026, one Form 8-K filing reported a material cybersecurity incident under Item 1.05: Park Dental Partners, Inc., filed 13 October 2026 (accession 0001104659-26-115541).
- The EDGAR full-text search for "Item 1.05" on Form 8-K over the same window returned two results; the second was an audit committee charter exhibit filed by another company, which does not report an incident and is excluded (re-run 11 Nov 2026).
- Quest Diagnostics Incorporated disclosed a cybersecurity matter under Item 8.01 rather than Item 1.05 in an 8-K filed 22 October 2026 (accession 0000947871-26-000941). The full number of Item 8.01 cyber disclosures in the window is UNKNOWN until the classification rule is stated.
- No 8-K/A amending an earlier Item 1.05 report was found for the window, by the method above (count 0; amendment coverage of the query UNKNOWN).
- Item 1.05 is the item a company uses for an incident it has judged material; Item 8.01 carries a disclosure without that judgment, so the two lines are reported separately.
- The count for 30–31 October 2026, and so for the full month of October, is UNKNOWN in this edition.
| Line | 1–29 Oct 2026 |
|---|---|
| 8-K, Item 1.05 (material cybersecurity incident) | 1: Park Dental Partners, Inc. |
| 8-K, Item 8.01 (other events; cyber disclosure) | Quest Diagnostics Incorporated. Full count UNKNOWN. |
| 8-K/A amending an earlier Item 1.05 | 0 (amendment coverage of the query UNKNOWN) |
Each counted filing has a desk note on the record: Park Dental Partners, Item 1.05, a material cybersecurity incident and Quest Diagnostics, Item 8.01.
For how the two items read, see SEC 8-K Item 1.05 cybersecurity incident disclosures.
How this count is made
What was reviewed. Current reports on Form 8-K filed with the SEC on EDGAR that report a cybersecurity incident under Item 1.05 (material cybersecurity incidents), plus a separate line for 8-Ks that disclose a cybersecurity incident under Item 8.01 (other events).
Date window. EDGAR filing dates from 1 October 2026 to 29 October 2026, cut off at 12:00 ET on 29 October 2026. Filings on 30 and 31 October 2026 are not in this edition; the full-month count is UNKNOWN until they are added.
How filings were found. An EDGAR full-text search for the exact phrase "Item 1.05" on Form 8-K for the window (the query). Every hit was then read to confirm that the item reports an incident rather than mentioning the item in passing. The Item 8.01 line comes from Distributed Risk's list_cyber_incident_filings tool, which reads EDGAR; the rule it uses to classify an Item 8.01 filing as a cyber disclosure is UNKNOWN on this page.
What counts. A filing counts once, on its EDGAR filing date. Exhibits that only quote "Item 1.05" (for example, an audit committee charter) are excluded. Totals are by filing date, not incident date; the incident can be earlier.
Amendments. 8-K/A filings that amend an earlier Item 1.05 report are counted on their own line. Whether the linked query captures 8-K/A: UNKNOWN.
Limits.
- Only Form 8-K filers are in the count.
- A company that discloses an incident in a different filing (for example a periodic report) does not appear here.
- Full-text search returns boilerplate; each hit is read before counting, so the count depends on that reading.
- The count says nothing about the size or cause of any incident.