Microsoft has resolved a bug that caused Windows Defender to crash after a recent security update, resulting in 0xc0000005 access violation errors on some affected systems. Microsoft Defender is a security software designed to provide real-time protection against malware, viruses, ransomware, and spyware on Windows, macOS, Linux, Android, and iOS devices. According to reports on social media and Microsoft's support site, users began seeing "Threat service has stopped. Restart it now" error messages on Windows 10 and Windows 11 devices starting Tuesday afternoon, prompting some affected customers to reinstall the operating system. "Beginning this morning, quick or full scans are failing, and will occasionally fail to the point where the Defender service needs to be restarted," one Windows system admin said.
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) warned that hackers are exploiting a critical-severity remote code execution (RCE) flaw in the Windows Internet Key Exchange (IKE) Service Extensions component. Also known as MS-IKEE, this is a set of additional capabilities Microsoft added to the IKE Protocol, including authentication via cryptographically generated addresses (CGAs), denial-of-service protection, and easier interoperability with non-Internet Protocol Security (IPsec)–capable peers. Tracked as CVE-2026-33824, this RCE vulnerability impacts all supported Windows 10, Windows 11, and Windows Server releases, and it allows attackers without privileges to gain code execution by sending maliciously crafted packets to unpatched Windows systems through UDP ports 500 or 4500.
Over 50,000 exposed Stripe API keys show how leaked secrets can enable fraud, data access and account abuse within hours. Ransomnews researchers have documented a large-scale leak of Stripe merchant API keys found exposed in public code repositories, GitHub Actions logs, and misconfigured web servers, with over 50,000 unique keys identified in total. The research is practical rather than theoretical: the team tested a sample of the keys, found a meaningful portion still active, and documented exactly how quickly a fraudster could exploit them. The answer is fast. “A dataset published on a data-trading forum on 18 August 2026 contains live Stripe API keys for 659 merchant accounts, along with roughly 35 GB of customer and payment data pulled from them.” reads the report published by Ransomnews. “Ransomnews analysed the files offline and reported the exposure to Stripe before publishing. Stripe itself was not compromised. The keys belong to merchants.” Researchers said that after finding an active Stripe API key, they were able to access a merchant’s customer list, create a fraudulent payment link and make a $1 test charge within 17 hours. The key alone was enough to perform these actions, highlighting the risks of exposed credentials and insufficient API protections. The operations a live Stripe secret key unlocks are extensive: listing customers and their stored payment methods, creating charges and payment intents, issuing refunds to attacker-controlled accounts, modifying webhook endpoints to intercept future payment notifications, and in some cases accessing connected accounts if the merchant had enabled Stripe Connect. A secret key is not a partial credential. It’s full API access. The sources of the leaked keys are unsurprising to anyone who has done developer security work. GitHub repositories — both public and accidentally made public, account for the largest share, typically through hardcoded keys in configuration files, .env files committed without a corresponding .gitignore entry, or keys left in code comments. GitHub Actions build logs are the second major source: when a workflow prints environment variables for debugging, any secret that wasn’t properly masked ends up in a log that anyone with repository access can read. Misconfigured web servers are another major source of exposed Stripe API keys. Researchers found over 3,000 servers revealing Stripe-related strings, with about 12% containing keys that worked against the Stripe API. The source of the 659 exposed merchant keys is unclear, but likely includes infostealer logs, public repositories, exposed environment files and misconfigured backups. The collector’s real advantage was systematically validating the keys, accessing each account and organizing the stolen data. “The dataset doesn’t say, and we are not going to guess at a single source for 659 separate merchants. The realistic candidates are the ordinary ones: secret keys sitting in infostealer logs lifted from developer machines, keys committed to public repositories, keys left in exposed environment files, keys pulled out of misconfigured backups. Stripe’s own documentation says the company scans for exactly this, and describes finding merchant keys on repositories and package registries.” concludes the report. “What the collector added was patience. Gathering keys is common. Validating several hundred of them, then systematically walking the API for each account and archiving the results into a consistent folder structure, is a different level of effort.” Stripe does provide automatic secret scanning through GitHub’s partner program, which flags Stripe keys found in public repositories and can trigger automatic revocation when a merchant opts in. The problem is that opt-in rate is low, the scanning doesn’t cover private repositories, and it has no coverage over build logs, web server misconfigurations, or other platforms where keys surface. Ransomnews also found that some merchants had rotated their keys after a GitHub exposure but left the old keys active, possibly because Stripe doesn’t revoke keys on rotation unless you explicitly delete the old one. The remediation is not complicated. Audit your current Stripe keys against your version control history to see if any have ever been committed. Rotate any key that has touched a public repository, a build log, or a configuration file that wasn’t explicitly protected. Enable Stripe’s restricted keys for any integration that doesn’t need full account access — a webhook handler doesn’t need the ability to create charges. And enable Stripe Radar rules to flag unusual charge patterns that might indicate someone else is using your key before you’ve noticed it’s gone. Follow me on Twitter: @securityaffairs and Facebook and Mastodon Pierluigi Paganini (SecurityAffairs – hacking, data leak)
The Cybersecurity and Infrastructure Security Agency (CISA) said Tuesday that the Medusa ransomware gang has breached more than 500 critical infrastructure organizations in the United States since June 2021. This was revealed in a joint advisory in coordination with the Department of Health and Human Services (HHS) and the Federal Bureau of Investigation (FBI). "As of April 2026, Medusa actors have impacted more than 500 victims across multiple critical infrastructure sectors, including Healthcare and Public Health, Defense Industrial Base, Critical Manufacturing, Government Services and Facilities, Information Technology, and Financial Services," they said. "Other victims include organizations in the medical, education, legal, insurance, technology, and manufacturing industries." This is an update to a joint report published in March 2025, which said the Medusa ransomware operation had impacted an estimated over 300 critical infrastructure organizations.
U.S. Cybersecurity and Infrastructure Security Agency (CISA) adds Apple macOS, Microsoft SharePoint, Broadcom VMware vCenter, and Microsoft IKE flaws to its Known Exploited Vulnerabilities catalog. The U.S. Cybersecurity and Infrastructure Security Agency (CISA) added the following vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog: CVE-2026-33824 (CVSS score: 9.8) – Microsoft Internet Key Exchange (IKE) Service Extensions Double Free Vulnerability CVE-2026-55040 (CVSS score: 9.1) Microsoft SharePoint Weak Authentication Vulnerability CVE-2026-59310 (CVSS score: 9.8) Broadcom VMware vCenter Path Traversal Vulnerability CVE-2026-65400 Apple macOS Improper Authentication Vulnerability CVE-2026-33824 is a Windows Internet Key Exchange (IKE) Service Extensions Remote Code Execution Vulnerability. This critical flaw in Windows IKE service extensions could allow remote attackers to execute code on affected systems. Systems with IKE enabled are at risk, though blocking UDP ports 500 and 4500 can reduce exposure from external threats. However, internal attackers may still exploit it for lateral movement, so rapid patching is strongly recommended. CVE-2026-55040 is a critical SharePoint authentication bypass. An unauthenticated attacker can exploit weaknesses in JWT validation to forge tokens and impersonate any SharePoint user, including administrators. “A critical authentication bypass vulnerability exists in SharePoint Server Subscription Edition’s JWT token validation pipeline. The root cause is a chain of four distinct weaknesses that, when combined, allow an unauthenticated remote attacker to forge a valid JWT and impersonate any SharePoint site user.” wrote Rapid7. The exploit chain works by sending a JWT with “alg: none” in the outer header so no signature is required, using SharePoint’s own STS certificate thumbprint to resolve a signing key without verification, and then passing a non-empty but never-verified signature like “AAAA.” The result is a fully forged token that SharePoint accepts as legitimate. Defused researchers observed attackers using the Rapid7 POC for CVE-2026-55040 against our SharePoint their honeypots. CVE-2026-59310 flaw is a Path Traversal Vulnerability that allows an attacker with network access to execute arbitrary code. “VMware vCenter contains a directory traversal vulnerability in the Syslog server. Broadcom has evaluated the severity of this issue to be in the Critical severity range with a maximum CVSSv3 base score of 9.8.”states the advisory.”A malicious actor with network access to vCenter may exploit this issue to execute arbitrary code.” CVE-2026-65400 is an Improper Authentication Vulnerability that sits in macOS’s built-in Screen Sharing feature, the remote desktop tool baked into every Mac.On August 15, 2026, the Dutch National Cyber Security Centre confirmed active exploitation of a critical macOS authentication flaw, less than two weeks after Apple shipped the fix. Apple’s fix improved how the system manages authentication state, closing a gap that let attackers on the network authenticate to Screen Sharing without valid credentials at all. Apple patched this issue with the release of macOS Tahoe 26.6.1, macOS Sequoia 15.7.9, and macOS Sonoma 14.8.9, crediting researcher Alfredo Pesoli (@__rev) at Bynario Atlas (bynar.io) for the discovery. “An attacker on the network may be able to authenticate to Screen Sharing without valid credentials” reads the advisory. According to Binding Operational Directive (BOD) 22-01: Reducing the Significant Risk of Known Exploited Vulnerabilities, FCEB agencies have to address the identified vulnerabilities by the due date to protect their networks against attacks exploiting the flaws in the catalog. Experts also recommend that private organizations review the Catalog and address the vulnerabilities in their infrastructure. CISA orders federal agencies to fix the flaws by August 21, 2026 Follow me on Twitter: @securityaffairs and Facebook and Mastodon Pierluigi Paganini (SecurityAffairs – hacking, CISA)
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Tuesday added four critical vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog, stating they are being exploited in the wild. The shortcomings added to the KEV catalog are listed below - CVE-2026-65400 (CVSS score: 9.8) - An improper authentication vulnerability impacting Apple macOS that could allow an
Microsoft Defender Experts have linked more than 30 web domains to MacSync Stealer, a macOS-focused information stealer, after correlating recurring endpoint and network behaviors across changing infrastructure, tracing the malware from payload retrieval through data collection, staging, and exfiltration. The tech giant said it required multiple endpoint and network behaviors to align before
Comcast is promoting WiFi-based motion detection as a part of its new Xfinity Shield home protection platform, allowing routers and wireless devices to detect people moving through a home without cameras or motion sensors. This feature was announced as part of a new Xfinity Shield product offering on Tuesday, a new application suite that combines cybersecurity, physical home monitoring, and family safety features through Xfinity WiFi and the Xfinity app. Part of this new offering is WiFi Shield, which is included at no additional cost for Xfinity Internet customers with compatible gateways. It combines Xfinity's CyberSecure network protection, Family Settings, and WiFi Motion, with Home Watch, Away Watch, and Dark Watch modes used to control when notifications are generated. Comcast is also launching Shield Select for $15 per month, which adds an indoor camera, door/window sensor, cloud video storage, and 24/7 urgent response functionality.
We provide guidance for preparing for and mitigating large-scale credential attacks, focusing on recent campaigns targeting security vendors' devices. The post Threat Brief: Mitigating Large-Scale Credential Attacks (Updated August 18) appeared first on Unit 42.
A Heights Finance breach exposed personal and financial data of over 1.2 million people after hackers compromised a third-party cloud platform. Heights Finance is a U.S. consumer finance company that provides personal loans and related lending services, mainly to customers who may have limited access to traditional bank credit. It is part of Heights Finance Holdings Co. Heights Finance Holdings is notifying more than 1.2 million people that on May 7, 2026, Heights Finance discovered unauthorized access to a third-party cloud platform storing customer data. The company launched an investigation with external cybersecurity experts and notified federal law enforcement. “On May 7, 2026, Heights discovered that an unauthorized actor gained access to a cloud-based platform hosted by a third party that we use to store certain customer data. This activity was limited to the cloud-based platform only—it did not affect any of our loan management systems or other computer systems or networks. We immediately activated our incident response protocols, brought in outside cybersecurity specialists to investigate, and reported the incident to federal law enforcement.” reads the notice of data breach. “We have since confirmed that the cloud-based platform is secure and that there is no ongoing security threat. Our operations were not impacted by this incident and have continued safely and securely.” Heights said its internal systems and operations were not affected, the platform has been secured, and there is no ongoing threat. The compromised customer information included contact details, financial and bank account data, government IDs and dates of birth. The affected data varies by person and may involve Heights Finance customers, loan applicants, people who inquired about its products, or former borrowers of Curo Management and related brands. Heights Finance is offering affected individuals 24 months of free credit monitoring and identity protection. The company said dark web monitoring has found no evidence that the stolen data has been published. No threat actor has claimed responsibility, and no known ransomware or extortion group has been linked to the breach so far. Follow me on Twitter: @securityaffairs and Facebook and Mastodon Pierluigi Paganini (SecurityAffairs – hacking, Heights Finance)
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