Latest cybersecurity reporting from selected sources.

Microsoft has disclosed that a privilege escalation and a denial-of-service flaw in Defender has come under active exploitation in the wild

Also, Europol Cracks DDoS Networks, Mythos Finds Bugs, France Portal HitThis week, scam compounds. Attackers exploit flaws pre-disclosure. A crackdown on DDoS-for-hire. No Mythos for CISA, yes for Mozilla. France ID portal breach. Israeli and Venezuelan critical infrastructure targeted. Russian hacking in Ukraine. An Apache flaw. A ransomware negotiator aided BlackCat.

CVE-2025-53521 was initially disclosed in October as a high-severity denial-of-service (DoS) flaw, but new information has revealed the bug is actually much more dangerous.

CVE-2025-53521 was initially disclosed in October as a high-severity denial-of-service (DoS) flaw, but new information has revealed the bug is actually much more dangerous.

In early January 2026, KrebsOnSecurity revealed how a security researcher disclosed a vulnerability that was used to assemble Kimwolf, the world's largest and most disruptive botnet. Since then, the person in control of Kimwolf -- who goes by the handle "Dort" -- has coordinated a barrage of distributed denial-of-service (DDoS), doxing and email flooding attacks against the researcher and this author, and more recently caused a SWAT team to be sent to the researcher's home. This post examines what is knowable about Dort based on public information.

Microsoft on Monday disclosed that it automatically detected and neutralized a distributed denial-of-service (DDoS) attack targeting a single endpoint in Australia that measured 5.72 terabits per second (Tbps) and nearly 3.64 billion packets per second (pps)

Cisco on Wednesday disclosed that it became aware of a new attack variant that's designed to target devices running Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software releases that are susceptible to CVE-2025-20333 and CVE-2025-20362

Cybersecurity researchers have disclosed details of a new botnet that customers can rent access to conduct distributed denial-of-service (DDoS) attacks against targets of interest

Citrix warns that patching recently disclosed vulnerabilities that can be exploited to bypass authentication and launch denial-of-service attacks may also break login pages on NetScaler ADC and Gateway appliances. [...]

Cybersecurity researchers have called attention to a new campaign that's actively exploiting a recently disclosed critical security flaw in Langflow to deliver the Flodrix botnet malware

Simple denial-of-service blunder turned out to be a remote unauth code exec disaster Suspected Chinese government spies have been exploiting a newly disclosed critical bug in Ivanti VPN appliances since mid-March. This is now at least the third time in three years these snoops have been pwning these products.…

Cybersecurity researchers have disclosed details of a new vulnerability impacting Google's Quick Share data transfer utility for Windows that could be exploited to achieve a denial-of-service (DoS) or send arbitrary files to a target's device without their approval

A Mirai botnet variant has been found exploiting a newly disclosed security flaw impacting Four-Faith industrial routers since early November 2024 with the goal of conducting distributed denial-of-service (DDoS) attacks

Palo Alto Networks has disclosed a high-severity vulnerability impacting PAN-OS software that could cause a denial-of-service (DoS) condition on susceptible devices

Cybersecurity researchers have disclosed six security flaws in the Ollama artificial intelligence (AI) framework that could be exploited by a malicious actor to perform various actions, including denial-of-service, model poisoning, and model theft

Cloudflare has disclosed that it mitigated a record-breaking distributed denial-of-service (DDoS) attack that peaked at 3.8 terabits per second (Tbps) and lasted 65 seconds

A recently disclosed vulnerability in the Common Unix Printing System (CUPS) open-source printing system can be exploited by threat actors to launch distributed denial-of-service (DDoS) attacks with a 600x amplification factor. [...]

Cybersecurity researchers have disclosed details of a new distributed denial-of-service (DDoS) attack campaign targeting misconfigured Jupyter Notebooks

Multiple threat actors have been observed exploiting a recently disclosed security flaw in PHP to deliver remote access trojans, cryptocurrency miners, and distributed denial-of-service (DDoS) botnets

Multiple security flaws have been disclosed in Emerson Rosemount gas chromatographs that could be exploited by malicious actors to obtain sensitive information, induce a denial-of-service (DoS) condition, and even execute arbitrary commands