Enterprise Ransomware Defenses Block Top Threats Only 38% of the Time

Current Defenses Fail Against Leading Ransomware Two-Thirds of the Time

August 2026 testing of enterprise security stacks against top ransomware families found that current defenses block these threats less than 38% of the time, according to a new analysis published August 12. Every leading ransomware family tested successfully bypassed enterprise controls in the majority of attack simulations, despite overall improvements in perimeter security scores.

The testing focused on ransomware families most frequently deployed against enterprises in 2026. The sub-40% block rate means that organizations relying on standard endpoint detection, email filtering, and network monitoring are statistically more likely to experience a successful ransomware execution than to stop it. This data point directly undermines vendor claims of "comprehensive" or "multi-layered" protection and creates measurable liability for CISOs defending current security spending to boards.

For buyers, the implication is immediate: current stacks are not calibrated to the threats that matter most. The typical enterprise security budget allocates resources across prevention, detection, and response, but if prevention fails 62% of the time against known threats, the weighting needs to shift. This justifies increased investment in immutable backup, incident response retainers, and cyber insurance—not as secondary controls but as primary budget line items.

CISA Flags VPN and RDP as Ransomware Entry Points in New Gunra Advisory

On August 10, CISA published an advisory on Gunra, a ransomware-as-a-service operation that expanded from a single threat group in 2025 to a multi-affiliate model in 2026. The advisory explicitly identifies internet-facing VPN gateways and Remote Desktop Protocol systems as common entry points for Gunra affiliates targeting government, critical infrastructure, and enterprise networks.

CISA's mitigation guidance is unusually specific: prioritize patching of known exploited vulnerabilities in VPN and RDP infrastructure, implement network segmentation, and maintain offline, immutable backups. This is the U.S. federal government telling enterprises that their remote access architecture is a primary ransomware vector and that traditional backup strategies are insufficient.

The competitive impact is clear. CISA's guidance strengthens the business case for zero-trust network access platforms from Zscaler, Palo Alto Networks (Prisma Access), and Cisco (Duo, Secure Connect) against legacy IPsec VPNs. It arms privileged access management vendors—CyberArk, Delinea—with a federal endorsement of their core value proposition. And it positions immutable backup platforms from Rubrik, Cohesity, and Commvault as compliance requirements rather than optional enhancements.

For procurement teams, the advisory changes the risk calculus on third-party vendor access. Any external partner connecting via VPN or RDP now requires higher scrutiny in vendor security reviews and potentially mandates specific access controls as contract terms.

SharePoint RCE Vulnerability Actively Exploited to Deploy Ransomware

Ransomware operators are exploiting CVE-2026-45659, a high-severity remote code execution vulnerability in Microsoft SharePoint, to encrypt entire enterprise networks, according to an August 11 threat intelligence briefing. More than 8,500 SharePoint servers are currently exposed to the internet and in scope for exploitation.

The vulnerability allows attackers to execute arbitrary code on unpatched SharePoint servers and use that foothold to distribute ransomware across connected systems. CISA has confirmed active exploitation in ransomware campaigns, moving this from a theoretical risk to an operational emergency for enterprises running on-premises SharePoint Server 2019 or Subscription Edition.

This creates immediate budget pressure in two directions. First, it justifies emergency spending on SharePoint patching, external attack surface management tools (Wiz, Palo Alto Prisma Cloud, Tenable.asm), and vulnerability management platforms (Tenable, Rapid7, Qualys, Automox, Ivanti). Second, it accelerates migration decisions away from self-hosted SharePoint toward SharePoint Online or competing SaaS collaboration platforms—Slack, Atlassian Confluence Cloud, Box, Google Workspace—that shift patching responsibility to the vendor.

For enterprises still running on-premises SharePoint, the 8,500 exposed server count provides a specific data point to justify either hardening investments or cloud migration in board presentations. For SaaS collaboration vendors, CVE-2026-45659 is a named vulnerability tied directly to ransomware that can be referenced in competitive positioning against self-hosted alternatives.

What to Watch

The sub-40% block rate against top ransomware families is not a temporary gap—it reflects a structural mismatch between how security budgets are allocated and where risk actually concentrates. Expect increased scrutiny of prevention-heavy security postures and accelerated adoption of assume-breach architectures that prioritize containment and recovery over perimeter defense.

CISA's specific guidance on VPN, RDP, and backup hygiene will appear in audit requirements, cyber insurance applications, and board-level risk discussions throughout 2026 and 2027. Enterprises that have delayed ZTNA or PAM projects now have federal justification to reprioritize them.

For SharePoint operators, the vulnerability window is closing. Patch CVE-2026-45659 immediately or expect to explain the decision not to in the event of an incident. For procurement teams evaluating collaboration platforms, this is evidence that vendor-managed patching is a measurable risk control, not a convenience feature.