Windows | Breaking Cybersecurity News | The Hacker News

Security researcher Chaotic Eclipse (aka Nightmare-Eclipse and MSNightmare) has released a new Windows BitLocker bypass dubbed GreatXML , a day after they published an exploit for Microsoft Defender. "This was an accidental discovery, it took a total of 4 hours to find this," the researcher said in a post on Blogger. "If you ever attempted to use Windows Defender Offline Scan , you're automatically vulnerable to a BitLocker bypass. I'm unsure if you can still trigger the bug without ever using the offline scan feature, because you can definitely." The exploit works as follows - Copy an XML file ("unattend.xml") and a recovery folder containing another XML file ("Recovery/WindowsRE/ReAgent.xml") to the root of the recovery partition. Reboot to Windows Recovery Environment ( WinRE ) by holding Shift while clicking Restart in the Windows power menu. If every step is followed correctly, the result is a shell spawned with unre...

Microsoft on Tuesday released fixes for a record 206 security vulnerabilities impacting its software portfolio, including three flaws that have been publicly disclosed at the time of release. Of the 206 flaws, 39 are rated Critical, and 167 are rated Important in severity. This includes 63 privilege escalation, 56 remote code execution, 30 information disclosure, 27 spoofing, 20 security feature bypass, seven denial-of-service, and three tampering vulnerabilities. The patches also include two non-Microsoft CVEs, a privilege escalation vulnerability impacting Windows Kernel ( CVE-2025-10263 ) and a UEFI Secure Boot security feature bypass ( CVE-2026-8863 ). They are in addition to more than 350 security flaws that Google has addressed in Chromium, which is used in Microsoft's Edge browser. Topping the list of fixes is CVE-2026-45657 (CVSS score: 9.8), a use-after-free flaw affecting Windows Kernel that could result in remote code execution. "An attacker could exploi...

The anonymous security researcher going by the name Chaotic Eclipse (aka Nightmare-Eclipse) has released a proof-of-concept (PoC) exploit for yet another Microsoft Defender zero-day named RoguePlanet . "The exploit is a race condition, so it's a hit or miss," the researcher, who published the exploit under a new GitHub account "MSNightmare" said . "I have managed to get a 100% success rate on some machines while it struggled to work on others." Should the exploit succeed, the result is a shell with SYSTEM-level privileges, granting the attacker the ability to run arbitrary code or perform unauthorized actions. The researcher said the exploit has been tested on Windows 11 and 10 machines with the June 2026 Patch Tuesday updates installed, meaning the exploit works on the up-to-date versions of the desktop operating system. That said, the exploit does not work on Windows Server instances in its current form since "standard users cannot mou...

Microsoft has come out strongly in favor of Coordinated Vulnerability Disclosure (CVD), urging the research community to share their findings and give affected vendors an opportunity to better understand the impact and address them before they are publicly disclosed. The development comes after a researcher named Chaotic Eclipse (aka Nightmare-Eclipse) disclosed details of multiple zero-day vulnerabilities affecting various Windows components, including Defender and BitLocker, over the past month, citing a breakdown in Microsoft's handling of the vulnerability disclosure process. "In recent weeks, several zero-day vulnerabilities have been publicly disclosed," the tech giant said . "The details of these vulnerabilities were not shared with Microsoft prior to release, and the disclosures put our customers at unnecessary risk." "In response to the unnecessary risk created by these disclosures, our security teams have been working around the clock to ...

1 Introduction This article provides a technical analysis of how many Windows kernel mode drivers can be interacted with from user mode without the hardware they were developed for. This work was motivated by driver-oriented vulnerability research and the need to evaluate the exploitability of individual findings, which frequently affect code whose reachability is hardware-gated. The methodology presented here should help anyone determine whether a particular Windows kernel mode driver vulnerability remains reachable - and thus potentially exploitable - even in the absence of the hardware the driver was developed for. The reader is expected to have basic Windows driver knowledge, especially regarding device objects. The rest of this article is written with the assumption that the reader is already familiar with the concepts described in the introduction article: Anatomy of Access: Windows Device Objects from a Security Perspective . Just like the introduction article, this resou...

Microsoft on Tuesday released a mitigation for a BitLocker bypass vulnerability named YellowKey following its public disclosure last week. The zero-day flaw, now tracked as CVE-2026-45585 , carries a CVSS score of 6.8. It has been described as a BitLocker security feature bypass. "Microsoft is aware of a security feature bypass vulnerability in Windows publicly referred to as 'YellowKey,'" the tech giant said in an advisory. "The proof of concept for this vulnerability has been made public, violating coordinated vulnerability best practices." The issue impacts Windows 11 version 26H1 for x64-based Systems, Windows 11 Version 24H2 for x64-based Systems, Windows 11 Version 25H2 for x64-based Systems, Windows Server 2025, and Windows Server 2025 (Server Core installation). YellowKey was disclosed by a security researcher named Chaotic Eclipse (aka Nightmare-Eclipse). It essentially involves placing specially crafted 'FsTx' files on a USB driv...

Chaotic Eclipse, the security researcher behind the recently disclosed Windows flaws, YellowKey and GreenPlasma , has released a proof-of-concept (PoC) for a Windows privilege escalation zero-day flaw that grants attackers SYSTEM privileges on fully patched Windows systems. Codenamed MiniPlasma , the vulnerability impacts "cldflt.sys," which refers to the Windows Cloud Files Mini Filter Driver, and resides in a routine named "HsmOsBlockPlaceholderAccess." It was originally reported to Microsoft by Google Project Zero researcher James Forshaw in September 2020. Although it was assumed that the shortcoming was fixed by Microsoft in December 2020 as part of CVE-2020-17103 , Chaotic Eclipse said further investigation has uncovered that the "exact same issue [...] is actually still present, unpatched." "I'm unsure if Microsoft just never patched the issue or the patch was silently rolled back at some point for unknown reasons. The original PoC by...

An anonymous cybersecurity researcher who disclosed three Microsoft Defender vulnerabilities has returned with two more zero-days involving a BitLocker bypass and a privilege escalation impacting Windows Collaborative Translation Framework (CTFMON). The security defects have been codenamed YellowKey and GreenPlasma , respectively, by the researcher, who goes by the online aliases Chaotic Eclipse and Nightmare-Eclipse. The researcher described YellowKey as "one of the most insane discoveries I ever found," likening the BitLocker bypass to functioning as a backdoor, as the bug is present only in the Windows Recovery Environment ( WinRE ), a built-in framework designed to troubleshoot and repair common unbootable operating system issues. YellowKey affects Windows 11 and Windows Server 2022/2025. At a high level, it involves copying specially crafted "FsTx" files on a USB drive or the EFI partition, plugging the USB drive into the target Windows computer with Bit...

Microsoft has unveiled a new multi-model artificial intelligence (AI)-driven system called MDASH to facilitate vulnerability discovery and remediation at scale, adding that it's being tested by some customers as part of a limited private preview. MDASH, short for m ulti-mo d el a gentic s canning h arness, is designed as a model-agnostic system that uses bespoke AI agents for different vulnerability classes to autonomously discover, validate, and prove exploitable defects in complex codebases like Windows. "Unlike single-model approaches, the harness orchestrates more than 100 specialized AI agents across an ensemble of frontier and distilled models to discover, debate, and prove exploitable bugs end-to-end," Taesoo Kim, vice president of agentic security at Microsoft, said . MDASH is envisioned as a "structured pipeline" that ingests a codebase and produces validated, proven findings through a series of actions. It starts with analyzing the source code t...

Microsoft on Tuesday released patches for 138 security vulnerabilities spanning its product portfolio, although none of them have been listed as publicly known or under active attack. Of the 138 flaws, 30 are rated Critical, 104 are rated Important, three are rated Moderate, and one is rated Low in severity. As many as 61 vulnerabilities are classified as privilege escalation bugs, followed by 32 remote code execution, 15 information disclosure, 14 spoofing, eight denial-of-service, six security feature bypass, and two tampering flaws. The update list also includes a vulnerability that was patched by AMD ( CVE-2025-54518 , CVSS score: 7.3) this month. It relates to a case of improper isolation of shared resources within the CPU operation cache on Zen 2-based products that could allow an attacker to corrupt instructions executed at a different privilege level, potentially resulting in privilege escalation. The patches are also in addition to 127 security flaws that Google has add...

Microsoft on Monday revised its advisory for a now-patched, high-severity security flaw impacting Windows Shell to acknowledge that it has been actively exploited in the wild. The vulnerability in question is CVE-2026-32202 (CVSS score: 4.3), a spoofing vulnerability that could allow an attacker to access sensitive information. It was addressed as part of its Patch Tuesday update for this month. "Protection mechanism failure in Windows Shell allows an unauthorized attacker to perform spoofing over a network," Microsoft noted in an alert. "An attacker would have to send the victim a malicious file that the victim would have to execute." "An attacker who successfully exploited the vulnerability could view some sensitive information (Confidentiality) but not all resources within the impacted component may be divulged to the attacker. The attacker cannot make changes to disclosed information (Integrity) or limit access to the resource (Availability)."...

Microsoft on Tuesday released updates to address a record 169 security flaws across its product portfolio, including one vulnerability that has been actively exploited in the wild. Of these 169 vulnerabilities, 157 are rated Important, eight are rated Critical, three are rated Moderate, and one is rated Low in severity. Ninety-three of the flaws are classified as privilege escalation, followed by 21 information disclosure, 21 remote code execution, 14 security feature bypass, 10 spoofing, and nine denial-of-service vulnerabilities. Also included among the 169 flaws are four non-Microsoft issued CVEs impacting AMD (CVE-2023-20585), Node.js (CVE-2026-21637), Windows Secure Boot (CVE-2026-25250), and Git for Windows (CVE-2026-32631). The updates are in addition to 78 vulnerabilities that have been addressed in its Chromium-based Edge browser since the update that was released last month . T...

Google has made Device Bound Session Credentials  ( DBSC ) generally available to all Windows users of its Chrome web browser, months after it began testing the security feature in open beta. The public availability is currently limited to Windows users on Chrome 146, with macOS expansion planned in an upcoming Chrome release. "This project represents a significant step forward in our ongoing efforts to combat session theft, which remains a prevalent threat in the modern security landscape," Google's Chrome and Account Security teams said in a Thursday post. Session theft involves the covert exfiltration of session cookies from the web browser, either by gathering existing ones or waiting for a victim to log in to an account, to an attacker-controlled server. Typically, this happens when users inadvertently download information-stealing malware into their systems. These stealer malware families – of which there are many, such as ...

Your attack surface no longer lives on one operating system, and neither do the campaigns targeting it. In enterprise environments, attackers move across Windows endpoints, executive MacBooks, Linux infrastructure, and mobile devices, taking advantage of the fact that many SOC workflows are still fragmented by platform.  For security leaders, this creates a costly operational gap : slower validation, limited early-stage visibility, more escalations, and more time for attackers to steal credentials, establish persistence, or move deeper before the response fully begins. The Multi-OS Attack Problem SOCs Aren’t Ready For A multi-OS attack can turn one threat into several different investigations at once. The campaign may follow a different path depending on the system it reaches, which breaks the speed and consistency SOC teams rely on during early triage. Instead of moving through one clear validation pro...

A recently disclosed security flaw patched by Microsoft may have been exploited by the Russia-linked state-sponsored threat actor known as APT28 , according to new findings from Akamai. The vulnerability in question is CVE-2026-21513 (CVSS score: 8.8), a high-severity security feature bypass affecting the MSHTML Framework. "Protection mechanism failure in MSHTML Framework allows an unauthorized attacker to bypass a security feature over a network," Microsoft noted in its advisory for the flaw. It was fixed by the Windows maker as part of its February 2026 Patch Tuesday update. However, the tech giant also noted that the vulnerability had been exploited as a zero-day in real-world attacks, crediting the Microsoft Threat Intelligence Center (MSTIC), Microsoft Security Response Center (MSRC), and Office Product Group Security Team, along with Google Threat Intelligence Group (GTIG), for reporting it. In a hypothetical attack scenario, a threat actor could weaponize th...

The U.S. Federal Bureau of Investigation (FBI) has warned of an increase in ATM jackpotting incidents across the country, leading to losses of more than $20 million in 2025. The agency said 1,900 ATM jackpotting incidents have been reported since 2020, out of which 700 took place last year. In December 2025, the U.S. Department of Justice (DoJ) said about $40.73 million has been collectively lost to jackpotting attacks since 2021. "Threat actors exploit physical and software vulnerabilities in ATMs and deploy malware to dispense cash without a legitimate transaction," the FBI said in a Thursday bulletin. The jackpotting attacks involve the use of specialized malware, such as Ploutus, to infect ATMs and force them to dispense cash. In most cases, cybercriminals have been observed gaining unauthorized access to the machines by opening an ATM face with widely available generic keys. There are at least two different ways by which the malware is deployed: Removing the A...

Microsoft has announced a three-phase approach to phase out New Technology LAN Manager (NTLM) as part of its efforts to shift Windows environments toward stronger, Kerberos-based options. The development comes more than two years after the tech giant revealed its plans to deprecate the legacy technology, citing its susceptibility to weaknesses that could facilitate relay attacks and allow bad actors to gain unauthorized access to network resources. NTLM was formally deprecated in June 2024 and no longer receives updates. "NTLM consists of security protocols originally designed to provide authentication, integrity, and confidentiality to users," Mariam Gewida, Technical Program Manager II at Microsoft, explained. "However, as security threats have evolved, so have our standards to meet modern security expectations. Today, NTLM is susceptible to various attacks, including replay and man-in-the-middle attacks, due to its use of weak cryptography." Despite the d...

The pro-Russian hacktivist group known as CyberVolk (aka GLORIAMIST) has resurfaced with a new ransomware-as-a-service (RaaS) offering called VolkLocker that suffers from implementation lapses in test artifacts, allowing users to decrypt files without paying an extortion fee. According to SentinelOne, VolkLocker (aka CyberVolk 2.x) emerged in August 2025 and is capable of targeting both Windows and Linux systems. It's written in Golang. "Operators building new VolkLocker payloads must provide a bitcoin address, Telegram bot token ID, Telegram chat ID, encryption deadline, desired file extension, and self-destruct options," security researcher Jim Walter said in a report published last week. Once launched, the ransomware attempts to escalate privileges, performs reconnaissance and system enumeration, including checking local MAC address prefixes against known virtualization vendors like Oracle and VMware. In the next stage, it lists all available drives and determin...

Microsoft has silently plugged a security flaw that has been exploited by several threat actors since 2017 as part of the company's November 2025 Patch Tuesday updates , according to ACROS Security's 0patch . The vulnerability in question is CVE-2025-9491 (CVSS score: 7.8/7.0), which has been described as a Windows Shortcut (LNK) file UI misinterpretation vulnerability that could lead to remote code execution. "The specific flaw exists within the handling of .LNK files," according to a description in the NIST National Vulnerability Database (NVD). "Crafted data in an .LNK file can cause hazardous content in the file to be invisible to a user who inspects the file via the Windows-provided user interface. An attacker can leverage this vulnerability to execute code in the context of the current user." In other words, these shortcut files are crafted such that viewing their properties in Windows conceals the malicious commands executed by them out of the u...

Microsoft on Tuesday released patches for 63 new security vulnerabilities identified in its software, including one that has come under active exploitation in the wild. Of the 63 flaws, four are rated Critical and 59 are rated Important in severity. Twenty-nine of these vulnerabilities are related to privilege escalation, followed by 16 remote code execution, 11 information disclosure, three denial-of-service (DoS), two security feature bypass, and two spoofing bugs. The patches are in addition to the 27 vulnerabilities the Windows maker addressed in its Chromium-based Edge browser since the release of October 2025's Patch Tuesday update. The zero-day vulnerability that has been listed as exploited in Tuesday's update is CVE-2025-62215 (CVSS score: 7.0), a privilege escalation flaw in Windows Kernel. The Microsoft Threat Intelligence Center (MSTIC) and Microsoft Security Response Center (MSRC) have been credited with discovering and reporting the issue. "Concurre...