Latest cybersecurity reporting from selected sources.

Claroty Warns of Downtime, 'Devastating' Impact of Vulnerabilities in OT SystemsVulnerabilities in backup power devices and heating and cooling control systems widely used in data centers could enable remote cyberattacks and result in costly downtime and "devastating" operational impact, according to new research from OT security firm Claroty.

Anthropic's AI Model Exposes How Unprepared Enterprises Are to RespondAnthropic's announcement this week of Claude Mythos Preview frontier model capable of finding zero-days flaws humans may miss is both a warning and a call to action for CIOs: The way enterprises have been managing cybersecurity is about to change forever, and they need to get ready.

Researcher: If Exploited, Bug Could Crash Hospital Medical Imaging SystemsThe Cybersecurity Infrastructure and Security Agency is warning of a high severity in Grassroots DICOM, an open-source library commonly used for medical imaging products, that if exploited could allow an attacker to send a specially crafted file resulting in a denial-of-service situation.

Also: Spanish Hacker Granted Russian Asylum, Microsoft Patches Zero-DaysThis week, a CISA warning, Nest footage in Nancy Guthrie case, Signal phishing. Spanish hacker, Russian asylum. Spanish ministry services offline. BYOVD ransomware. The Conduent breach hit Volvo. Microsoft patched zero-days. ZeroDayRAT targeted devices. The SmarterMail breach. Another Fortinet flaw.

Also, CIRO Phishing Breach, Ingram Micro Ransomware and CVE SurgeThis week, DOGE posted sensitive data on an outside server. A phishing attack affected 750,000 Canadians. A hacktivism warning from the U.K. NCSC. An Ingram Micro breach. CVEs surged in 2025. SK Telecom challenged a fine. Researchers disclosed Chainlit flaws. North Korean hackers abused VS Code.

Vendor Ships Emergency Fixes, Warning Flaw Facilitates Full System CompromiseAttackers are targeting a zero-day vulnerability in Cisco's Unified Communications and Webex products that facilitates remote code execution and root-level access to the underlying operating system, risking full system compromise. Cisco has released patches, warning that no workarounds exist.

Mirion Medical Says Bugs Are Fixed in New Release of BioDose/NMIS SoftwareU.S. federal authorities are warning that several high-severity vulnerabilities discovered in Mirion Medical Co. inventory tracking software used by nuclear medicine departments could allow attackers to modify program executables and gain access to sensitive information.

Rapid7's Christiaan Beek on Ransomware Tactics and How to Mitigate Attacks in 2026Ransomware attacks are reaching record highs, and 2026 may be even worse, said Christiaan Beek, senior director of threat intel and analytics at Rapid7. He warns that hackers are exploiting vulnerabilities as soon as they're disclosed, and they're focusing on flaws in devices on the network edge.

Agency Warns Vertikal Systems Vulnerabilities Could Help Hackers Access DataU.S. federal authorities are warning about vulnerabilities in hospital information management systems from Romanian firm Vertikal Systems that could allow hackers to obtain and disclose patient data. The affected systems are used mostly by smaller hospitals and clinics outside the United States.

NTLM Reflection Attack Strikes AgainA three-month old flaw in a network protocol for file sharing used by Microsoft is under active exploitation, warns the U.S. Cybersecurity and Infrastructure Security Agency. The flaw's exploitation bypasses mitigations Microsoft has built over the years to prevent NTLM reflection attacks.

Also, Akira Ransomware Resumes Attacks Via SonicWall FlawsThis week, the Vidar infostealer, BlackDB admin, Akira ransomware hackers and Patch Tuesday. A warning for British bankers, a Cursor flaw, a Brazilian dating app shut down. KazMunayGas said it wasn't hacked. Wealthsimple and Hello Gym data breaches. A macOS backdoor hid in plain sight for years.

Robust Security Reviews of AI-Generated Code Required, Warns StudyGenies might grant magic wishes, but they inevitably come with consequences. Enter artificial intelligence coding assistants, which many developers say help them write code more quickly. New research shows that this productivity comes with a security cost, and must be mitigated.

CISA Issues Emergency Directive Requiring Federal Agencies to Fix FlawA vulnerability in Exchange hybrid deployments could allow attackers to escalate privileges and gain administrative access to cloud-based environments. Microsoft said Tuesday there is no evidence of its exploitation and "strongly" recommended installing hot fix updates made available in April.

Semperis Warns of Flaw in Windows Server 2025 Delegated Managed Service AccountsA critical cryptographic flaw in Windows Server 2025's delegated Managed Service Accounts, or dMSAs, allows attackers to generate passwords for every managed service account across an Active Directory forest and create a backdoor, Semperis researchers found.

Also: CISA Warns of Unpatched Train Brake VulnerabilityThis week: Louis Vuitton and Co-op confirm breaches, unpatched train brake flaw, Barclays fined £42M pounds for financial crime failures, secret U.K. program relocated thousands of Afghans, ex-soldier pleads guilty to hacking, Ukrainian hackers claim hit on Russian drone supplier.

Hacker Claims to Have Exploited Flaw in Oracle WebLogic Server, Sold Stolen DataSeychelles Commercial Bank is warning customers that a hacker stole their personal information - but no money - from their accounts after breaching its systems. The hacker involved claims to have stolen and sold two gigabytes of customer data from the bank, which paid no ransom.

Always Secure MCP Servers Connecting LLMs to External Systems, Experts WarnWarning: Popular technology designed to make it easy for artificial intelligence tools to connect with external applications and data sources can be turned to malicious use. Researchers discovered two separate vulnerabilities tied to tools in the ecosystem around model context protocol, or MCP.

Akamai Researchers Flag 'BadSucessor' in Windows Server 2025An unpatched flaw in Windows Server 2025 that is "trivial" to exploit and present in the default configuration is full domain compromised, warns new research from Akamai. The flaw is present in a new account type known as delegated managed service accounts, or dMSA.

Tech Giant Says Threat Actors Are Exploiting a Flaw in Widely-Targeted Windows ToolRansomware threat actors are exploiting a zero-day vulnerability discovered in a highly targeted Windows logging system tool in a campaign in part targeting U.S. IT and real estate sectors, Microsoft confirmed in a Tuesday blog post urging customers to apply available patches.

Also: Lee Enterprises Recovering From Ransomware Attack, an Ivanti POCThis week, a FBI warning on Ghost ransomware, Lee Enterprises confirmed its ransomware attack, a proof-of-concept for Ivanti EPM flaws and a cybersecurity flaw in a Xerox machine. Also, a Chinese cyberespionage hacker apparently moonlighted as a ransomware attacker and NioCorp hit by a cyber heist.