# Microsoft issues Defender signature fix for scan crashes

_Wednesday, August 19, 2026 at 7:14 AM EDT · Security · Latest · Tier 2 — Notable_

![Microsoft issues Defender signature fix for scan crashes — Primary](https://www.bleepstatic.com/content/hl-images/2021/05/26/Microsoft-Defender.jpg)

Microsoft says it has fixed a Windows Defender bug that caused quick and full scans to fail on some Windows 10 and Windows 11 systems after a recent security update. The company said the remedy is included in Microsoft Defender Antivirus signature update version 1.457.236.0 or later, and advised customers to apply the latest update or enable automatic updates. Affected systems displayed access-violation errors and could require a Defender service restart.

## Sources

- [BleepingComputer](https://www.bleepingcomputer.com/news/microsoft/microsoft-fixes-known-issue-causing-windows-defender-crashes/)

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Canonical: https://techandbusiness.org/newswire/EOFLb0zN_lEDdfJZgt3SOb
Retrieved: 2026-08-19T14:28:31.961Z
Publisher: Tech & Business (techandbusiness.org)