Windows September 2025 Updates Disrupt SMBv1 Connections
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Microsoft's September 2025 Windows security updates are causing connection failures to SMBv1 shares over NetBIOS over TCP/IP (NetBT). The issue affects multiple Windows client and server platforms. Microsoft is working on a fix and has provided a temporary workaround. SMBv1 has been deprecated since 2014 due to security vulnerabilities and was superseded by SMBv2 and later protocols.
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15.09.2025 15:48 📰 1 articles · ⏱ 2d ago
Windows September 2025 Updates Cause SMBv1 Connection Failures
Microsoft's September 2025 Windows security updates are causing connection issues to SMBv1 shares over NetBIOS over TCP/IP (NetBT). The issue affects multiple Windows client and server platforms. Microsoft is working on a fix and has provided a temporary workaround involving allowing traffic on TCP port 445. SMBv1 has been deprecated since 2014 due to security vulnerabilities and was superseded by SMBv2 and later protocols.
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- Microsoft says Windows September updates break SMBv1 shares — www.bleepingcomputer.com — 15.09.2025 15:48
Information Snippets
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The affected platforms include Windows 11 24H2/23H2/22H2, Windows 10 22H2/21H2, Windows Server 2025, and Windows Server 2022.
First reported: 15.09.2025 15:48📰 1 source, 1 articleShow sources
- Microsoft says Windows September updates break SMBv1 shares — www.bleepingcomputer.com — 15.09.2025 15:48
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The issue occurs when either the SMB client or server has the September 2025 security update installed.
First reported: 15.09.2025 15:48📰 1 source, 1 articleShow sources
- Microsoft says Windows September updates break SMBv1 shares — www.bleepingcomputer.com — 15.09.2025 15:48
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Microsoft recommends allowing traffic on TCP port 445 as a temporary workaround to resume SMB connections.
First reported: 15.09.2025 15:48📰 1 source, 1 articleShow sources
- Microsoft says Windows September updates break SMBv1 shares — www.bleepingcomputer.com — 15.09.2025 15:48
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SMBv1 was deprecated in 2014 and is no longer installed by default in Windows 10 version 1709 and later.
First reported: 15.09.2025 15:48📰 1 source, 1 articleShow sources
- Microsoft says Windows September updates break SMBv1 shares — www.bleepingcomputer.com — 15.09.2025 15:48
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Microsoft has been advising against using SMBv1 due to its lack of security improvements and vulnerabilities.
First reported: 15.09.2025 15:48📰 1 source, 1 articleShow sources
- Microsoft says Windows September updates break SMBv1 shares — www.bleepingcomputer.com — 15.09.2025 15:48