Denial of Service
Citrix warns admins to patch new NetScaler RCE flaw immediately
Citrix has warned IT administrators to patch systems immediately against a new critical vulnerability affecting NetScaler ADC networking appliances and NetScaler Gateway secure remote access solutions. Tracked as CVE-2026-107406, this flaw stems from a memory overflow weakness that attackers can exploit to gain remote code execution (RCE) on targeted devices or trigger a denial-of-service state […]
Cisco warns of critical flaws allowing Nexus switch takeover
Cisco released security advisories for five critical vulnerabilities in its NX-OS data center network operating system that could be exploited to run arbitrary code with root privileges on Nexus switches. If remote code execution cannot be achieved, an attacker could exploit the vulnerabilities to crash processes and force the vulnerable device to reload, resulting in […]
Citrix patches NetScaler SAML zero-day exploited in attacks
Citrix has released emergency updates for a new NetScaler denial-of-service vulnerability tracked as CVE-2026-88779 that has been exploited in zero-day attacks, with researchers investigating whether it can also be exploited for remote code execution. The vulnerability is a memory buffer flaw affecting NetScaler ADC and NetScaler Gateway appliances using SAML authentication with Gateway or AAA […]
CISA orders feds to patch exploited Citrix flaws by Wednesday
The Cybersecurity and Infrastructure Security Agency (CISA) has ordered U.S. government agencies over the weekend to secure their systems against attacks exploiting two critical Citrix NetScaler vulnerabilities. Citrix released security updates to address the flaws (tracked as CVE-2026-88771 and CVE-2026-88772) days after national cybersecurity agencies, IT suppliers, and security teams began privately contacting Citrix customers […]
New Windows Defender zero-day blocks Microsoft antivirus updates
Over the weekend, security researcher Abdelhamid Naceri (also known as Nightmare Eclipse) released another Microsoft Defender zero-day exploit that blocks antivirus updates. Naceri named it BigDiskBuster and said it is similar to another Defender zero-day known as UnDefend, which he released in April and that allowed standard users to block definition updates. The security researcher added […]
New GPUThor attack defeats NVIDIA ECC protection for root access
A newly disclosed Rowhammer attack called GPUThor can bypass error-correcting code (ECC) protections on NVIDIA GPUs, enabling denial-of-service (DoS) and root-level privilege escalation. In a paper published by the University of Toronto, researchers say that GPUThor achieves far more practical bit-flip rates than past concepts like their own GPUHammer or GPUBreach, which became irrelevant after ECC was introduced. […]
Citrix urges admins to patch new NetScaler flaws as soon as possible
Citrix has warned customers to immediately secure their systems against two vulnerabilities affecting NetScaler Gateway secure remote access solutions and NetScaler ADC networking appliances. The most severe of the two, tracked as CVE-2026-19490, can allow remote attackers without privileges to bypass authentication when the appliance is configured as an AAA virtual server or as a Gateway […]
Cisco warns of ASA and FTD VPN flaw exploited to crash devices
Cisco is warning that a high-severity denial-of-service vulnerability in Secure Firewall ASA and Threat Defense (FTD) software is being actively exploited in attacks to remotely crash affected devices. The flaw, tracked as CVE-2026-20349, has a severity score of 8.6 and impacts devices running Cisco Secure Firewall Adaptive Security Appliance (ASA) or Secure Firewall Threat Defense […]
Cisco warns of high-severity ClamAV flaws with public exploits
Cisco warned of two high-severity vulnerabilities affecting the Secure Endpoint Connector that allow threat actors to crash the ClamAV scanning process in denial-of-service (DoS) attacks. The security flaws (tracked as CVE-2026-20337 and CVE-2026-20338) were found in the ZIP archive parser of ClamAV (Clam AntiVirus), the open-source and cross-platform engine used to scan files for malware. As Cisco explained […]
HollowByte DDoS flaw bloats OpenSSL server memory with 11-byte payload
A vulnerability dubbed HollowByte allows unauthenticated attackers to trigger a denial-of-service (DoS) condition on OpenSSL servers with a malicious payload of just 11 bytes. The OpenSSL team has silently fixed the vulnerability (no identifier assigned) and backported the patch to older releases. Because the OpenSSL software is the foundational backbone for secure internet communication, organizations […]