Security Domain
Communication & Network Security
Network architecture, protocols, secure communication channels, and network attacks.
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← All domainsCisco Catalyst SD-WAN Manager CVE-2026-20262 Actively Exploited — Arbitrary File Overwrite Escalates to Root
A file upload vulnerability in Cisco Catalyst SD-WAN Manager is under active exploitation, allowing an attacker with network-operator level access to overwrite arbitrary files on the underlying operating system and escalate privileges to root. CISA added CVE-2026-20262 to the Known Exploited Vulnerabilities catalogue on 16 June, setting a federal remediation deadline.
PAN-OS GlobalProtect CVE-2026-0257 (CVSS 9.3): Authentication Bypass Exploited Against Government and Critical Infrastructure
Palo Alto Networks has confirmed active exploitation of CVE-2026-0257, a critical authentication bypass in the GlobalProtect gateway that allows an unauthenticated attacker to establish VPN sessions as arbitrary users. CISA has added the flaw to the Known Exploited Vulnerabilities catalogue, and Palo Alto's Unit 42 has observed exploitation targeting government and critical infrastructure networks since at least 12 June.
Ivanti Sentry CVE-2026-10523 (CVSS 9.9): Second Critical Flaw Chains with CVE-2026-10520 for Complete Device Takeover
Ivanti has disclosed a second critical vulnerability in Sentry — CVE-2026-10523, an authentication bypass scoring CVSS 9.9 — that chains with the previously patched CVE-2026-10520 (CVSS 10.0) to enable complete unauthenticated takeover of the MDM gateway. Organisations that deployed the initial patch must apply additional updates; the two CVEs affect overlapping but distinct code paths.
Gentlemen Ransomware Worm: Using Network Segmentation to Contain Propagation Before Detection
The confirmed worm capability in the Gentlemen ransomware payload — propagating via SMB exploitation and credential reuse — changes the containment calculus for enterprise incident response. Effective network segmentation stops worm propagation at VLAN boundaries. This guide maps the segmentation controls that constrain Gentlemen's lateral movement.
HTTP.sys CVE-2026-47291: Quantifying Wormable Risk Across the Windows Server Estate
Three days after the June Patch Tuesday, CVE-2026-47291 in HTTP.sys remains unpatched on a significant proportion of enterprise Windows Server infrastructure. This article maps the attack surface — which services expose HTTP.sys, how the worm propagation would function, and what network controls reduce the blast radius while patching is in progress.
Palo Alto Networks Patches PAN-OS Command Injection CVE-2026-0273 Across All Active Branches
Palo Alto Networks has patched CVE-2026-0273, a command injection vulnerability in the PAN-OS web management interface that allows authenticated administrators to execute arbitrary OS commands on the firewall. The vulnerability affects PAN-OS versions 10.1 through 11.2 and all active GlobalProtect gateway configurations. Updates are available across all supported branches.
Linux Kernel CVE-2026-23111: nf_tables Use-After-Free Enables Container Escape and Root Privilege Escalation
A use-after-free vulnerability in the Linux kernel's nf_tables netfilter subsystem allows unprivileged users to escalate to root and break container isolation. Public proof-of-concept code published 9 June makes this an immediate remediation priority across all major Linux distributions running kernel versions 5.15 through 6.10.
CVE-2026-50751: Check Point Security Gateway Authentication Bypass Actively Exploited in Ransomware Campaigns
CISA added CVE-2026-50751 to the Known Exploited Vulnerabilities catalogue on 8 June with a three-day remediation deadline and confirmed ransomware campaign use. The vulnerability is a CVSS 9.3 authentication bypass in Check Point Security Gateway's IKEv1 VPN protocol handling that allows unauthenticated attackers to bypass remote access VPN authentication entirely. An emergency hotfix is available.
VPN Gateway Security: Hardening the Network Perimeter Device That Attackers Target First
VPN gateways and remote access concentrators have become the most frequently exploited initial access vector in enterprise network intrusions. With critical vulnerabilities regularly disclosed in Palo Alto GlobalProtect, Citrix NetScaler, Fortinet FortiGate, and now Check Point Security Gateway, this guide covers the security hardening and monitoring posture that reduces exposure regardless of which vendor's appliance your organisation runs.
CVE-2026-46243 and the CIFS Attack Surface: Network-Layer Hardening for Linux SMB Environments
CVE-2026-46243 exploits a flaw in the Linux kernel CIFS client subsystem reachable from local shell access. But the broader CIFS/SMB attack surface extends beyond this single CVE — SMB signing enforcement, unauthenticated share access, and uncontrolled NTLM relay paths are network-level risks that compound the impact of any CIFS kernel vulnerability. This article covers network hardening for Linux environments that use SMB/CIFS mounts.
Windows Netlogon CVE-2026-41089 (CVSS 9.8): Unauthenticated Domain Controller RCE Now Actively Exploited
Belgium's Centre for Cybersecurity (CCB) confirmed active exploitation of CVE-2026-41089 on 29 May — a stack-based buffer overflow in the Windows Netlogon Remote Protocol (MS-NRPC) that allows unauthenticated remote code execution on domain controllers. CVSS 9.8. A public PoC is available. Patch domain controllers as an emergency priority.
Citrix NetScaler CVE-2026-3055 Exploitation Escalates — Fortinet Confirms Large-Scale Attacks on Internet-Facing ADC
Fortinet's threat intelligence team has confirmed large-scale active exploitation of CVE-2026-3055, the Citrix NetScaler SAML IDP memory overread vulnerability (CVSSv4 9.3) patched in March. More than 65 days after the patch was available, thousands of internet-facing NetScaler ADC appliances remain unpatched and are being targeted by automated exploitation frameworks.
MiniPlasma: PoC-Released Windows Zero-Day Exploits Cloud Files Mini Filter Driver for SYSTEM Access
A researcher published a working proof-of-concept for a Windows zero-day — dubbed MiniPlasma — that exploits the Cloud Files Mini Filter Driver to achieve SYSTEM-level access on fully-patched Windows 10, Windows 11, and Windows Server 2022/2025. Microsoft has not issued a patch or an out-of-band advisory. All unmitigated Windows systems with cloud sync enabled are affected.
GNU SASL CVE-2026-48829: DIGEST-MD5 Parser Crash Affects Enterprise Mail Servers and LDAP Stacks
A NULL pointer dereference in GNU SASL's DIGEST-MD5 authentication mechanism (CVE-2026-48829, CVSS 7.5) allows a remote attacker to crash any service using GNU SASL for DIGEST-MD5 authentication by sending a malformed authentication token. Debian and other distribution security advisories published 24 May. Services affected include Postfix, Cyrus IMAP, and LDAP servers using SASL for authentication.
Linux Kernel CVE-2026-43503: Networking skbuff Frag-Transfer Bug Causes Memory Corruption — CVSS 8.8
Linux kernel stable branch patches published 23 May address CVE-2026-43503, a CVSS 8.8 memory corruption vulnerability in two networking helper functions that incorrectly handle the SKBFL_SHARED_FRAG flag during fragment transfers. The bug affects the skb_shift and __pskb_copy_fclone functions across multiple kernel versions and can be triggered by crafted network traffic on affected configurations.
Ubiquiti UniFi OS Security Bulletin 064: Three CVSS 10.0 Vulnerabilities Enable Unauthenticated Full Device Compromise
Ubiquiti published Security Bulletin 064 on 22 May disclosing five CVEs in UniFi OS devices, three of which score CVSS 10.0: an improper access control flaw, a path traversal enabling arbitrary file read and write, and a command injection that provides root shell access — all exploitable without authentication from the network. Enterprise environments using UniFi Wi-Fi infrastructure must update immediately.
PAN-OS GlobalProtect CVE-2026-0257: Rapid7 Confirms Second Exploitation Wave — CISA Adds to KEV
Rapid7 MDR confirmed on 21 May that a second, larger exploitation wave of CVE-2026-0257, an authentication bypass in Palo Alto Networks GlobalProtect VPN, began on 21 May targeting enterprise sectors not covered in the initial wave. CISA added the CVE to the Known Exploited Vulnerabilities catalogue with a 1 June remediation deadline. The vulnerability affects PAN-OS 10.2, 11.1, 11.2, and 12.1 as well as Prisma Access.
SonicWall Gen6 SSL-VPN: Patch for CVE-2024-12802 Fails to Close MFA Bypass — Akira Ransomware in 86% of Compromises
ReliaQuest published research on 19 May confirming that SonicWall's official firmware patch for CVE-2024-12802 on Generation 6 SSL-VPN devices requires six manual reconfiguration steps to fully close the MFA bypass vulnerability. Devices that reached end-of-life on 16 April 2026 will receive no further patches. Akira ransomware is present in 86% of SonicWall-involved intrusion claims reviewed by ReliaQuest.
Pwn2Own Demonstrates Second Distinct SharePoint RCE Chain — Five Days After Patch Tuesday Fixed CVE-2026-40365
Researchers at Pwn2Own Berlin 2026 demonstrated a multi-bug SharePoint Server remote code execution chain that is entirely distinct from CVE-2026-40365, the SharePoint RCE patched in the 12 May Patch Tuesday. The new chain, targeting SharePoint's server-side processing pipeline, has no patch and will not receive one for up to 90 days.
Cisco SD-WAN CVE-2026-20182 Post-Compromise Forensics: Identifying Rogue Device Injection in Catalyst SD-WAN Deployments
CVE-2026-20182, the CVSS 10.0 Cisco Catalyst SD-WAN Manager zero-day added to CISA KEV on 14 May, was exploited before Cisco released the patch. Organisations that ran vManage on publicly accessible addresses during the exposure window must now forensically audit their SD-WAN device inventory and API authentication logs for signs of rogue device registration and traffic interception.
Microsoft Exchange Server Zero-Day CVE-2026-42897 Actively Exploited in XSS Attacks — OOB Mitigation Available, No Patch Yet
Microsoft disclosed an actively exploited cross-site scripting zero-day in Exchange Server (CVE-2026-42897) that allows attackers to inject malicious scripts into Outlook Web App sessions, hijack authenticated user sessions, and exfiltrate email content. No patch is available. Microsoft deployed an Emergency Exchange Mitigation Service (EEMS) rule as an interim control while a patch is developed.
Cisco Catalyst SD-WAN CVE-2026-20182 CVSS 10.0 Authentication Bypass Exploited as Zero-Day — Attackers Injecting Rogue SD-WAN Devices
Cisco disclosed a CVSS 10.0 authentication bypass in the Catalyst SD-WAN Manager that has been actively exploited as a zero-day, allowing unauthenticated attackers to inject rogue SD-WAN devices into the management plane and intercept or reroute enterprise WAN traffic. The vulnerability has been added to CISA's Known Exploited Vulnerabilities catalogue with a 72-hour patching deadline for federal agencies.
NGINX 18-Year-Old Heap Buffer Overflow CVE-2026-42945 — CVSS 9.2 Flaw Affects All Versions Since 0.6.27 Including Modern API Gateways
A heap buffer overflow in NGINX's chunked transfer encoding handler, present since version 0.6.27 released in 2008, has been assigned CVE-2026-42945 with a CVSS score of 9.2. The vulnerability affects all NGINX versions through the latest release and has potential for both denial-of-service and remote code execution. Patches are available and the broad deployment of NGINX as a web server, reverse proxy, and API gateway makes this a wide-impact event.
Critical Exim MTA Remote Code Execution CVE-2026-45185 — Use-After-Free in GnuTLS Shutdown Affects Millions of Linux Email Servers
A critical use-after-free vulnerability (CVE-2026-45185) in Exim's GnuTLS TLS session shutdown handler enables unauthenticated remote code execution on any Exim installation compiled with GnuTLS support. Exim is the default MTA on Debian, Ubuntu, and many Linux distributions, putting tens of millions of internet-facing mail servers at risk. Patches are available and should be applied immediately.