Microsoft today pushed software updates to fix a staggering 167 security vulnerabilities in its Windows operating systems and related software, including a SharePoint Server zero-day and a publicly disclosed weakness in Windows Defender dubbed “BlueHammer.” Separately, Google Chrome fixed its fourth zero-day of 2026, and an emergency update for Adobe Reader nixes an actively exploited flaw that can lead to remote code execution.

Redmond warns that attackers are already targeting CVE-2026-32201, a vulnerability in Microsoft SharePoint Server that allows attackers to spoof trusted content or interfaces over a network.

Mike Walters, president and co-founder of Action1, said CVE-2026-32201 can be used to deceive employees, partners, or customers by presenting falsified information within trusted SharePoint environments.

“This CVE can enable phishing attacks, unauthorized data manipulation, or social engineering campaigns that lead to further compromise,” Walters said. “The presence of active exploitation significantly increases organizational risk.”

Microsoft also addressed BlueHammer (CVE-2026-33825), a privilege escalation bug in Windows Defender. According to BleepingComputer, the researcher who discovered the flaw published exploit code for it after notifying Microsoft and growing exasperated with their response. Will Dormann, senior principal vulnerability analyst at Tharros, says he confirmed that the public BlueHammer exploit code no longer works after installing today’s patches.

Satnam Narang, senior staff research engineer at Tenable, said April marks the second-biggest Patch Tuesday ever for Microsoft. Narang also said there are indications that a zero-day flaw Adobe patched in an emergency update on April 11 — CVE-2026-34621 — has seen active exploitation since at least November 2025.

Adam Barnett, lead software engineer at Rapid7, called the patch total from Microsoft today “a new record in that category” because it includes nearly 60 browser vulnerabilities. Barnett said it might be tempting to imagine that this sudden spike was tied to the buzz around the announcement a week ago today of Project Glasswing — a much-hyped but still unreleased new AI capability from Anthropic that is reportedly quite good at finding bugs in a vast array of software.

But he notes that Microsoft Edge is based on the Chromium engine, and the Chromium maintainers acknowledge a wide range of researchers for the vulnerabilities which Microsoft republished last Friday.

“A safe conclusion is that this increase in volume is driven by ever-expanding AI capabilities,” Barnett said. “We should expect to see further increases in vulnerability reporting volume as the impact of AI models extend further, both in terms of capability and availability.”

Finally, no matter what browser you use to surf the web, it’s important to completely close out and restart the browser periodically. This is really easy to put off (especially if you have a bajillion tabs open at any time) but it’s the only way to ensure that any available updates get installed. For example, a Google Chrome update released earlier this month fixed 21 security holes, including the high-severity zero-day flaw CVE-2026-5281.

For a clickable, per-patch breakdown, check out the SANS Internet Storm Center Patch Tuesday roundup. Running into problems applying any of these updates? Leave a note about it in the comments below and there’s a decent chance someone here will pipe in with a solution.

Microsoft Corp. today pushed security updates to fix at least 77 vulnerabilities in its Windows operating systems and other software. There are no pressing “zero-day” flaws this month (compared to February’s five zero-day treat), but as usual some patches may deserve more rapid attention from organizations using Windows. Here are a few highlights from this month’s Patch Tuesday.

Image: Shutterstock, @nwz.

Two of the bugs Microsoft patched today were publicly disclosed previously. CVE-2026-21262 is a weakness that allows an attacker to elevate their privileges on SQL Server 2016 and later editions.

“This isn’t just any elevation of privilege vulnerability, either; the advisory notes that an authorized attacker can elevate privileges to sysadmin over a network,” Rapid7’s Adam Barnett said. “The CVSS v3 base score of 8.8 is just below the threshold for critical severity, since low-level privileges are required. It would be a courageous defender who shrugged and deferred the patches for this one.”

The other publicly disclosed flaw is CVE-2026-26127, a vulnerability in applications running on .NET. Barnett said the immediate impact of exploitation is likely limited to denial of service by triggering a crash, with the potential for other types of attacks during a service reboot.

It would hardly be a proper Patch Tuesday without at least one critical Microsoft Office exploit, and this month doesn’t disappoint. CVE-2026-26113 and CVE-2026-26110 are both remote code execution flaws that can be triggered just by viewing a booby-trapped message in the Preview Pane.

Satnam Narang at Tenable notes that just over half (55%) of all Patch Tuesday CVEs this month are privilege escalation bugs, and of those, a half dozen were rated “exploitation more likely” — across Windows Graphics Component, Windows Accessibility Infrastructure, Windows Kernel, Windows SMB Server and Winlogon. These include:

–CVE-2026-24291: Incorrect permission assignments within the Windows Accessibility Infrastructure to reach SYSTEM (CVSS 7.8)
–CVE-2026-24294: Improper authentication in the core SMB component (CVSS 7.8)
–CVE-2026-24289: High-severity memory corruption and race condition flaw (CVSS 7.8)
–CVE-2026-25187: Winlogon process weakness discovered by Google Project Zero (CVSS 7.8).

Ben McCarthy, lead cyber security engineer at Immersive, called attention to CVE-2026-21536, a critical remote code execution bug in a component called the Microsoft Devices Pricing Program. Microsoft has already resolved the issue on their end, and fixing it requires no action on the part of Windows users. But McCarthy says it’s notable as one of the first vulnerabilities identified by an AI agent and officially recognized with a CVE attributed to the Windows operating system. It was discovered by XBOW, a fully autonomous AI penetration testing agent.

XBOW has consistently ranked at or near the top of the Hacker One bug bounty leaderboard for the past year. McCarthy said CVE-2026-21536 demonstrates how AI agents can identify critical 9.8-rated vulnerabilities without access to source code.

“Although Microsoft has already patched and mitigated the vulnerability, it highlights a shift toward AI-driven discovery of complex vulnerabilities at increasing speed,” McCarthy said. “This development suggests AI-assisted vulnerability research will play a growing role in the security landscape.”

Microsoft earlier provided patches to address nine browser vulnerabilities, which are not included in the Patch Tuesday count above. In addition, Microsoft issued a crucial out-of-band (emergency) update on March 2 for Windows Server 2022 to address a certificate renewal issue with passwordless authentication technology Windows Hello for Business.

Separately, Adobe shipped updates to fix 80 vulnerabilities — some of them critical in severity — in a variety of products, including Acrobat and Adobe Commerce. Mozilla Firefox v. 148.0.2 resolves three high severity CVEs.

For a complete breakdown of all the patches Microsoft released today, check out the SANS Internet Storm Center’s Patch Tuesday post. Windows enterprise admins who wish to stay abreast of any news about problematic updates, AskWoody.com is always worth a visit. Please feel free to drop a comment below if you experience any issues apply this month’s patches.

Microsoft today pushed updates to fix at least 56 security flaws in its Windows operating systems and supported software. This final Patch Tuesday of 2025 tackles one zero-day bug that is already being exploited, as well as two publicly disclosed vulnerabilities.

Despite releasing a lower-than-normal number of security updates these past few months, Microsoft patched a whopping 1,129 vulnerabilities in 2025, an 11.9% increase from 2024. According to Satnam Narang at Tenable, this year marks the second consecutive year that Microsoft patched over one thousand vulnerabilities, and the third time it has done so since its inception.

The zero-day flaw patched today is CVE-2025-62221, a privilege escalation vulnerability affecting Windows 10 and later editions. The weakness resides in a component called the “Windows Cloud Files Mini Filter Driver” — a system driver that enables cloud applications to access file system functionalities.

“This is particularly concerning, as the mini filter is integral to services like OneDrive, Google Drive, and iCloud, and remains a core Windows component, even if none of those apps were installed,” said Adam Barnett, lead software engineer at Rapid7.

Only three of the flaws patched today earned Microsoft’s most-dire “critical” rating: Both CVE-2025-62554 and CVE-2025-62557 involve Microsoft Office, and both can exploited merely by viewing a booby-trapped email message in the Preview Pane. Another critical bug — CVE-2025-62562 — involves Microsoft Outlook, although Redmond says the Preview Pane is not an attack vector with this one.

But according to Microsoft, the vulnerabilities most likely to be exploited from this month’s patch batch are other (non-critical) privilege escalation bugs, including:

–CVE-2025-62458 — Win32k
–CVE-2025-62470 — Windows Common Log File System Driver
–CVE-2025-62472 — Windows Remote Access Connection Manager
–CVE-2025-59516 — Windows Storage VSP Driver
–CVE-2025-59517 — Windows Storage VSP Driver

Kev Breen, senior director of threat research at Immersive, said privilege escalation flaws are observed in almost every incident involving host compromises.

“We don’t know why Microsoft has marked these specifically as more likely, but the majority of these components have historically been exploited in the wild or have enough technical detail on previous CVEs that it would be easier for threat actors to weaponize these,” Breen said. “Either way, while not actively being exploited, these should be patched sooner rather than later.”

One of the more interesting vulnerabilities patched this month is CVE-2025-64671, a remote code execution flaw in the Github Copilot Plugin for Jetbrains AI-based coding assistant that is used by Microsoft and GitHub. Breen said this flaw would allow attackers to execute arbitrary code by tricking the large language model (LLM) into running commands that bypass the user’s “auto-approve” settings.

CVE-2025-64671 is part of a broader, more systemic security crisis that security researcher Ari Marzuk has branded IDEsaster (IDE  stands for “integrated development environment”), which encompasses more than 30 separate vulnerabilities reported in nearly a dozen market-leading AI coding platforms, including Cursor, Windsurf, Gemini CLI, and Claude Code.

The other publicly-disclosed vulnerability patched today is CVE-2025-54100, a remote code execution bug in Windows Powershell on Windows Server 2008 and later that allows an unauthenticated attacker to run code in the security context of the user.

For anyone seeking a more granular breakdown of the security updates Microsoft pushed today, check out the roundup at the SANS Internet Storm Center. As always, please leave a note in the comments if you experience problems applying any of this month’s Windows patches.

Microsoft today released software updates to plug a whopping 172 security holes in its Windows operating systems, including at least two vulnerabilities that are already being actively exploited. October’s Patch Tuesday also marks the final month that Microsoft will ship security updates for Windows 10 systems. If you’re running a Windows 10 PC and you’re unable or unwilling to migrate to Windows 11, read on for other options.

The first zero-day bug addressed this month (CVE-2025-24990) involves a third-party modem driver called Agere Modem that’s been bundled with Windows for the past two decades. Microsoft responded to active attacks on this flaw by completely removing the vulnerable driver from Windows.

The other zero-day is CVE-2025-59230, an elevation of privilege vulnerability in Windows Remote Access Connection Manager (also known as RasMan), a service used to manage remote network connections through virtual private networks (VPNs) and dial-up networks.

“While RasMan is a frequent flyer on Patch Tuesday, appearing more than 20 times since January 2022, this is the first time we’ve seen it exploited in the wild as a zero day,” said Satnam Narang, senior staff research engineer at Tenable.

Narang notes that Microsoft Office users should also take note of CVE-2025-59227 and CVE-2025-59234, a pair of remote code execution bugs that take advantage of “Preview Pane,” meaning that the target doesn’t even need to open the file for exploitation to occur. To execute these flaws, an attacker would social engineer a target into previewing an email with a malicious Microsoft Office document.

Speaking of Office, Microsoft quietly announced this week that Microsoft Word will now automatically save documents to OneDrive, Microsoft’s cloud platform. Users who are uncomfortable saving all of their documents to Microsoft’s cloud can change this in Word’s settings; ZDNet has a useful how-to on disabling this feature.

Kev Breen, senior director of threat research at Immersive, called attention to CVE-2025-59287, a critical remote code execution bug in the Windows Server Update Service  (WSUS) — the very same Windows service responsible for downloading security patches for Windows Server versions. Microsoft says there are no signs this weakness is being exploited yet. But with a threat score of 9.8 out of possible 10 and marked “exploitation more likely,” CVE-2025-59287 can be exploited without authentication and is an easy “patch now” candidate.

“Microsoft provides limited information, stating that an unauthenticated attacker with network access can send untrusted data to the WSUS server, resulting in deserialization and code execution,” Breen wrote. “As WSUS is a trusted Windows service that is designed to update privileged files across the file system, an attacker would have free rein over the operating system and could potentially bypass some EDR detections that ignore or exclude the WSUS service.”

For more on other fixes from Redmond today, check out the SANS Internet Storm Center monthly roundup, which indexes all of the updates by severity and urgency.

Windows 10 isn’t the only Microsoft OS that is reaching end-of-life today; Exchange Server 2016, Exchange Server 2019, Skype for Business 2016, Windows 11 IoT Enterprise Version 22H2, and Outlook 2016 are some of the other products that Microsoft is sunsetting today.

If you’re running any Windows 10 systems, you’ve probably already determined whether your PC meets the technical hardware specs recommended for the Windows 11 OS. If you’re reluctant or unable to migrate a Windows 10 system to Windows 11, there are alternatives to simply continuing to use Windows 10 without ongoing security updates.

One option is to pay for another year’s worth of security updates through Microsoft’s Extended Security Updates (ESU) program. The cost is just $30 if you don’t have a Microsoft account, and apparently free if you register the PC to a Microsoft account. This video breakdown from Ask Your Computer Guy does a good job of walking Windows 10 users through this process. Microsoft emphasizes that ESU enrollment does not provide other types of fixes, feature improvements or product enhancements. It also does not come with technical support.

If your Windows 10 system is associated with a Microsoft account and signed in when you visit Windows Update, you should see an option to enroll in extended updates. Image: https://www.youtube.com/watch?v=SZH7MlvOoPM

Windows 10 users also have the option of installing some flavor of Linux instead. Anyone seriously considering this option should check out the website endof10.org, which includes a plethora of tips and a DIY installation guide.

Linux Mint is a great option for Linux newbies. Like most modern Linux versions, Mint will run on anything with a 64-bit CPU that has at least 2GB of memory, although 4GB is recommended. In other words, it will run on almost any computer produced in the last decade.

Linux Mint also is likely to be the most intuitive interface for regular Windows users, and it is largely configurable without any fuss at the text-only command-line prompt. Mint and other flavors of Linux come with LibreOffice, which is an open source suite of tools that includes applications similar to Microsoft Office, and it can open, edit and save documents as Microsoft Office files.

If you’d prefer to give Linux a test drive before installing it on a Windows PC, you can always just download it to a removable USB drive. From there, reboot the computer (with the removable drive plugged in) and select the option at startup to run the operating system from the external USB drive. If you don’t see an option for that after restarting, try restarting again and hitting the F8 button, which should open a list of bootable drives. Here’s a fairly thorough tutorial that walks through exactly how to do all this.

And if this is your first time trying out Linux, relax and have fun: The nice thing about a “live” version of Linux (as it’s called when the operating system is run from a removable drive such as a CD or a USB stick) is that none of your changes persist after a reboot. Even if you somehow manage to break something, a restart will return the system back to its original state.

As ever, if you experience any difficulties during or after applying this month’s batch of patches, please leave a note about it in the comments below.

Microsoft Corp. today issued security updates to fix more than 80 vulnerabilities in its Windows operating systems and software. There are no known “zero-day” or actively exploited vulnerabilities in this month’s bundle from Redmond, which nevertheless includes patches for 13 flaws that earned Microsoft’s most-dire “critical” label. Meanwhile, both Apple and Google recently released updates to fix zero-day bugs in their devices.

Microsoft assigns security flaws a “critical” rating when malware or miscreants can exploit them to gain remote access to a Windows system with little or no help from users. Among the more concerning critical bugs quashed this month is CVE-2025-54918. The problem here resides with Windows NTLM, or NT LAN Manager, a suite of code for managing authentication in a Windows network environment.

Redmond rates this flaw as “Exploitation More Likely,” and although it is listed as a privilege escalation vulnerability, Kev Breen at Immersive says this one is actually exploitable over the network or the Internet.

“From Microsoft’s limited description, it appears that if an attacker is able to send specially crafted packets over the network to the target device, they would have the ability to gain SYSTEM-level privileges on the target machine,” Breen said. “The patch notes for this vulnerability state that ‘Improper authentication in Windows NTLM allows an authorized attacker to elevate privileges over a network,’ suggesting an attacker may already need to have access to the NTLM hash or the user’s credentials.”

Breen said another patch — CVE-2025-55234, a 8.8 CVSS-scored flaw affecting the Windows SMB client for sharing files across a network — also is listed as privilege escalation bug but is likewise remotely exploitable. This vulnerability was publicly disclosed prior to this month.

“Microsoft says that an attacker with network access would be able to perform a replay attack against a target host, which could result in the attacker gaining additional privileges, which could lead to code execution,” Breen noted.

CVE-2025-54916 is an “important” vulnerability in Windows NTFS — the default filesystem for all modern versions of Windows — that can lead to remote code execution. Microsoft likewise thinks we are more than likely to see exploitation of this bug soon: The last time Microsoft patched an NTFS bug was in March 2025 and it was already being exploited in the wild as a zero-day.

“While the title of the CVE says ‘Remote Code Execution,’ this exploit is not remotely exploitable over the network, but instead needs an attacker to either have the ability to run code on the host or to convince a user to run a file that would trigger the exploit,” Breen said. “This is commonly seen in social engineering attacks, where they send the user a file to open as an attachment or a link to a file to download and run.”

Critical and remote code execution bugs tend to steal all the limelight, but Tenable Senior Staff Research Engineer Satnam Narang notes that nearly half of all vulnerabilities fixed by Microsoft this month are privilege escalation flaws that require an attacker to have gained access to a target system first before attempting to elevate privileges.

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

On Sept. 3, Google fixed two flaws that were detected as exploited in zero-day attacks, including CVE-2025-38352, an elevation of privilege in the Android kernel, and CVE-2025-48543, also an elevation of privilege problem in the Android Runtime component.

Also, Apple recently patched its seventh zero-day (CVE-2025-43300) of this year. It was part of an exploit chain used along with a vulnerability in the WhatsApp (CVE-2025-55177) instant messenger to hack Apple devices. Amnesty International reports that the two zero-days have been used in “an advanced spyware campaign” over the past 90 days. The issue is fixed in iOS 18.6.2, iPadOS 18.6.2, iPadOS 17.7.10, macOS Sequoia 15.6.1, macOS Sonoma 14.7.8, and macOS Ventura 13.7.8.

The SANS Internet Storm Center has a clickable breakdown of each individual fix from Microsoft, indexed by severity and CVSS score. Enterprise Windows admins involved in testing patches before rolling them out should keep an eye on askwoody.com, which often has the skinny on wonky updates.

AskWoody also reminds us that we’re now just two months out from Microsoft discontinuing free security updates for Windows 10 computers. For those interested in safely extending the lifespan and usefulness of these older machines, check out last month’s Patch Tuesday coverage for a few pointers.

As ever, please don’t neglect to back up your data (if not your entire system) at regular intervals, and feel free to sound off in the comments if you experience problems installing any of these fixes.