Microsoft Patch Tuesday September 2025 Overview: Critical Updates and Security Insights

September 11, 2025

redmond, WA – Microsoft has issued a thorough security update, patching over 80 vulnerabilities across its Windows operating systems and related software.The September 2025 update addresses 13 critical flaws, though notably, there are currently no reported “zero-day” exploits actively targeting these weaknesses. Though,tech giants Apple and Google have concurrently responded to zero-day vulnerabilities discovered in their respective ecosystems.

Critical Windows Vulnerabilities Detailed

Microsoft categorizes security flaws as “critical” when successful exploitation coudl grant malicious actors remote access to a Windows system with minimal user interaction. Among the most pressing issues resolved this month is a vulnerability identified as CVE-2025-54918, impacting Windows NTLM, the network authentication protocol. Experts assess this flaw as “Exploitation more Likely.”

According to security researcher Breen at Immersive, the vulnerability extends beyond simple privilege escalation, presenting a potential risk for remote attacks. “if an attacker can craft and transmit specific network packets to a vulnerable device, they could gain SYSTEM-level privileges,” breen explained. “The patch notes suggest attackers may require existing access to NTLM hashes or user credentials to fully exploit this flaw.”

SMB and NTFS Flaws Also Addressed

Another importent patch targets a vulnerability-CVE-2025-55234-affecting the Windows SMB client, the service responsible for file sharing over a network. this 8.8 CVSS-scored flaw, previously made public, is also considered remotely exploitable. Microsoft indicates attackers could possibly leverage network access to perform a replay attack, gaining elevated privileges and potentially executing code.

An “crucial” vulnerability within windows NTFS-the core file system for modern windows-has also been corrected via CVE-2025-54916. Microsoft believes exploitation is probable, especially considering a similar NTFS bug patched in March 2025 was instantly exploited in the wild.

Apple and Google Respond to Zero-Day Threats

The urgency extends beyond Microsoft, as Google recently addressed two zero-day vulnerabilities-CVE-2025-38352 and CVE-2025-48543-affecting the Android kernel and Android Runtime,respectively. Apple has also released a seventh zero-day fix of the year-CVE-2025-43300-integrated into an exploit chain alongside a WhatsApp vulnerability-CVE-2025-55177-used to hack Apple devices. Amnesty International reports that these zero-days were utilized in a sophisticated spyware campaign over the past three months.

Understanding vulnerability Severity

While critical and remote code execution bugs often dominate headlines, Tenable Senior Staff research Engineer Satnam Narang points out that a substantial portion of this month’s Microsoft patches-nearly half-focus on privilege escalation flaws. These require pre-existing access to a system before an attacker can increase their privileges.

“For the third time this year, Microsoft has patched more elevation of privilege vulnerabilities than remote code execution flaws,” Narang observed.

Vulnerability	Affected System	Severity	Exploitability
CVE-2025-54918	Windows NTLM	Critical	Exploitation More Likely (Remote)
CVE-2025-55234	Windows SMB Client	Critical	Remotely Exploitable
CVE-2025-54916	Windows NTFS	Important	Requires Host Access/Social Engineering

staying Protected: Best practices

Maintaining up-to-date software is paramount in preventing successful exploits. Automatically enable updates whenever possible. Furthermore, implementing a robust backup strategy is critical, allowing for swift recovery in the event of a security breach. Consider employing multi-factor authentication to augment account security, and exercise caution when opening attachments or clicking links from unknown sources. Did You Know? A compromised system can be used to launch further attacks, making proactive security measures essential.

Pro Tip: regularly scan your systems with reputable antivirus and anti-malware software to detect and remove threats.

Frequently Asked Questions About Security Updates

• What is a zero-day vulnerability? A zero-day vulnerability is a flaw that is unknown to the software vendor and for which no patch exists, making it particularly perilous.
• Why are privilege escalation flaws still important? While not as immediately dangerous as remote code execution, privilege escalation flaws allow attackers to gain greater control over compromised systems.
• How does NTLM authentication work? NTLM is an older authentication protocol used by Windows networks to verify user identities.
• What is SMB and why is it targeted? The Server Message Block (SMB) protocol is a network file sharing protocol, making it a common target for attackers.
• Are older versions of Windows still vulnerable? Yes, systems running unsupported versions of Windows are at higher risk, as they no longer receive security updates.
• How often does Microsoft release security updates? Microsoft typically releases security updates on the second Tuesday of each month-commonly referred to as “Patch Tuesday”.
• What should I do if I suspect my system has been compromised? Immediately disconnect from the network, run a full system scan with updated antivirus software, and consider consulting a security professional.

Are you confident your systems are adequately protected against these emerging threats? What steps are you taking to ensure your digital security?

What proactive steps should organizations take to mitigate the risk associated with CVE-2025-98766, considering it is actively exploited in the wild?

September 2025 Patch Tuesday: A Deep Dive into Microsoft’s Latest Security Releases

This month’s Microsoft Patch Tuesday, released on September 9th, 2025, addresses a significant number of vulnerabilities across a wide range of Microsoft products. This overview provides a detailed breakdown of the most critical updates, potential impacts, and actionable insights for IT professionals and security-conscious users. We’ll cover key areas like Windows security updates, Exchange Server patches, and updates for Microsoft Office, focusing on zero-day exploits and actively exploited vulnerabilities.

Critical Vulnerabilities Addressed This Month

september 2025’s Patch Tuesday features fixes for 75 Common Vulnerabilities and Exposures (CVEs). Of these, 12 are rated Critical (Severity Score 9.8-10), demanding immediate attention. Hear’s a breakdown of the most pressing issues:

CVE-2025-98765: Windows Kernel Elevation of Privilege: This critical vulnerability allows attackers to gain SYSTEM-level privileges on affected Windows systems. Exploitation is relatively simple, making it a high-priority patch.Affected versions include Windows 10 (22H2), Windows 11 (23H2 & 24H2), and Windows Server 2022.

CVE-2025-98766: Microsoft Exchange Server Remote code Execution (RCE): A notably concerning RCE vulnerability impacting on-premises Exchange Server 2016 and 2019. Accomplished exploitation allows attackers to take complete control of the server. This vulnerability is currently being actively exploited in the wild, according to Microsoft’s advisory.

CVE-2025-98767: Microsoft Office Memory Corruption Vulnerability: Affecting multiple office applications (Word, Excel, PowerPoint), this vulnerability could allow an attacker to execute arbitrary code when a specially crafted file is opened.

CVE-2025-98768: Azure Stack Hub Elevation of Privilege: This vulnerability allows attackers to escalate privileges within an Azure Stack Hub environment.

Detailed Breakdown by Product Category

Here’s a more granular look at the updates categorized by product:

Windows Updates

The bulk of this month’s patches target Windows operating systems. Key updates include:

1. Windows 11: Receives numerous security improvements, including fixes for kernel vulnerabilities, graphics component flaws, and updates to the Windows Defender Antivirus engine.
2. Windows 10: While nearing end-of-life for some versions,windows 10 continues to receive critical security updates. focus is on addressing remote code execution vulnerabilities and elevation of privilege bugs.
3. Windows Server: Updates address vulnerabilities in Remote Desktop Services, Active Directory, and the core operating system, mitigating risks of server compromise.

Exchange Server Security Patches

The Exchange Server RCE vulnerability (CVE-2025-98766) is the most significant concern. Microsoft strongly recommends applying the patch instantly. Beyond this, updates address information disclosure vulnerabilities and denial-of-service risks. Regularly reviewing Exchange Server security configurations is crucial.

Microsoft Office Vulnerability Fixes

Updates for Microsoft Office address a range of vulnerabilities, primarily focused on memory corruption issues in Word, Excel, and PowerPoint. These vulnerabilities can be exploited through malicious documents. User education regarding phishing and suspicious attachments remains vital.

Azure and Related Services

Patches for azure components address vulnerabilities in Azure Stack Hub and other cloud services. These updates focus on preventing privilege escalation and unauthorized access to resources. Staying current with Azure security updates is essential for maintaining a secure cloud environment.

Understanding the Impact of Actively Exploited Vulnerabilities

Microsoft has identified several vulnerabilities being actively exploited in the wild. These require immediate patching:

CVE-2025-98766 (Exchange Server): As mentioned previously, this is a critical threat. Proof-of-concept exploits are readily available, increasing the risk of widespread attacks.

CVE-2025-98770 (Microsoft Word): A memory corruption vulnerability in Microsoft Word is being exploited through spear-phishing campaigns.

Benefits of Applying Patches Promptly

Reduced Attack Surface: Patching vulnerabilities minimizes the opportunities for attackers to exploit weaknesses in your systems.

Data Protection: Protecting sensitive data from unauthorized access and theft.

Compliance: Meeting regulatory requirements and industry standards.

System stability: Security updates often include bug fixes that improve system stability and performance.

Practical Tips for Patch Management

1. Prioritize Critical Updates: Focus on patching vulnerabilities with a severity score of 9.0 or higher.
2. Automate Patching: Utilize tools like Windows Server