Denial of Service
F5 issues out-of-band patches for critical NGINX vulnerabilities
Cybersecurity company F5 has released out-of-band security updates to address multiple NGINX web server vulnerabilities, including two critical-severity flaws that could allow attackers to execute code on vulnerable systems. The two critical vulnerabilities were found in the ngx_http_v3_module (CVE-2026-42530) and the ngx_http_proxy_v2_module and ngx_http_grpc_module (CVE-2026-42055), and can be exploited by unauthenticated remote attackers to trigger […]
CISA: Hackers now exploit SolarWinds Serv-U flaw to crash servers
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) warned today that hackers are now actively exploiting a recently patched high-severity SolarWinds Serv-U flaw to crash servers. Serv-U is the company’s Windows and Linux file transfer software that offers Managed File Transfer (MFT) and FTP server capabilities, which allow users to securely exchange files via HTTP/HTTPS, […]
New ‘HTTP/2 Bomb’ DoS attack crashes web servers in under a minute
A new denial-of-service (DoS) attack dubbed HTTP/2 Bomb can be launched from a single machine to take down web servers within seconds. The technique works on default HTTP/2 configurations of major web servers, including NGINX, Apache HTTP Server, Microsoft IIS, Envoy, and Cloudflare Pingora. Discovered by OpenAI’s Codex software agent under the guidance of researchers […]
Microsoft warns of new Defender zero-days exploited in attacks
On Wednesday, Microsoft started rolling out security patches for two Defender vulnerabilities that have been exploited in zero-day attacks. The first one, tracked as CVE-2026-41091, is a privilege escalation security flaw affecting Microsoft Malware Protection Engine 1.1.26030.3008 and earlier, which provides the scanning, detection, and cleaning capabilities for Microsoft antivirus and antispyware software. This flaw stems […]
New Cisco DoS flaw requires manual reboot to revive devices
Cisco released security updates to fix a Crosswork Network Controller (CNC) and Network Services Orchestrator (NSO) denial-of-service (DoS) vulnerability that requires manually rebooting targeted systems for recovery. Large enterprises and service providers leverage the CNC software suite to simplify multivendor network management and operations handling with automation, while the NSO orchestration platform helps them manage […]
GitLab warns of high-severity 2FA bypass, denial-of-service flaws
GitLab has patched a high-severity two-factor authentication bypass impacting community and enterprise editions of its software development platform. Tracked as CVE-2026-0723, this vulnerability stems from an unchecked return value weakness in GitLab’s authentication services, allowing attackers who know the target’s account ID to circumvent two-factor authentication. “GitLab has remediated an issue that could have allowed an […]
UK govt. warns about ongoing Russian hacktivist group attacks
The U.K. government is warning of continued malicious activity from Russian-aligned hacktivist groups targeting critical infrastructure and local government organizations in the country in disruptive denial-of-service (DDoS) attacks. The attacks are aimed at taking websites offline and disabling services, the UK’s National Cyber Security Centre (NCSC) says in an alert today. Despite lacking sophistication, a DDoS attack […]
Palo Alto Networks warns of DoS bug letting hackers disable firewalls
Palo Alto Networks patched a high-severity vulnerability that could allow unauthenticated attackers to disable firewall protections in denial-of-service (DoS) attacks. Tracked as CVE-2026-0227, this security flaw affects next-generation firewalls (running PAN-OS 10.1 or later) and Palo Alto Networks’ Prisma Access configurations when the GlobalProtect gateway or portal is enabled. The cybersecurity company says that most […]
New Windows RasMan zero-day flaw gets free, unofficial patches
Free unofficial patches are available for a new Windows zero-day vulnerability that allows attackers to crash the Remote Access Connection Manager (RasMan) service. RasMan is a critical Windows system service that starts automatically, runs in the background with SYSTEM-level privileges, and manages VPN, Point-to-Point Protocol over Ethernet (PPoE), and other remote network connections. ACROS Security […]
New SonicWall SonicOS flaw allows hackers to crash firewalls
American cybersecurity company SonicWall urged customers today to patch a high-severity SonicOS SSLVPN security flaw that can allow attackers to crash vulnerable firewalls. Tracked as CVE-2025-40601, this denial-of-service vulnerability is caused by a stack-based buffer overflow impacting Gen8 and Gen7 (hardware and virtual) firewalls. “A Stack-based buffer overflow vulnerability in the SonicOS SSLVPN service allows a […]