Mainframe security is facing a critical inflection point, driven by the collision of long-standing identity and access management (IAM) blind spots with a rapidly evolving compliance landscape. For decades, mainframes have served as the backbone of major industries—banking, healthcare, government, and manufacturing—offering unsurpassed reliability and processing efficiency. Yet most have remained isolated from the persistent security innovations sweeping the broader IT ecosystem. Where enterprise IT teams have adopted cutting-edge IAM tools such as Okta or Azure Active Directory to enforce single sign-on (SSO), multi-factor authentication (MFA), and conditional access, mainframes have soldiered on with legacy controls like RACF, ACF2, or CA Top Secret. The result has been the development of two parallel security universes, rarely intersecting, and now creating a dangerous gap for organizations entrusted with critical data.
Despite mounting cybersecurity threats, the world of the mainframe has often been an afterthought for corporate security architects, who frequently assume that all critical infrastructure is protected by a unified IAM strategy. In reality, mainframe administrators have long maintained separate access controls and workflows—sometimes rooted in organizational silos, sometimes in the technical inertia associated with deeply entrenched legacy systems. This practice is not only outdated, but increasingly dangerous, as regulatory frameworks now expand their scope from “where data is stored” to “what data is protected”—obliterating old lines of convenience or exception.
Barbara Ballard, Principal Product Manager for Host Connectivity at Rocket Software, put it succinctly: “Just because it’s buried in a data center doesn’t mean it’s out of scope. Regulations don’t care what kind of box it runs on. They care that it contains sensitive data.” Her warning underscores a troubling reality—security leaders can no longer absolve themselves of responsibility for mainframe environments. As compliance and threat pressure mounts, this organizational inertia must yield to a more holistic, enterprise-wide strategy.
The implications are profound. Many mainframe environments still rely on little more than usernames and passwords for access, or—at best—bolt-on MFA systems that are disconnected from the company’s primary IAM platforms. These workarounds create both end-user friction and compliance nightmares. More critically, they introduce potential loopholes that sophisticated adversaries are increasingly adept at exploiting.
Auditors, meanwhile, are no longer satisfied with paper exceptions or trust in the inherent “hardened” nature of mainframes. Given the number and severity of real-world breaches resulting from legacy system exposures (see: NotPetya, Colonial Pipeline, WannaCry), security teams are now expected to demonstrate, in detail, how access to mainframes is controlled, monitored, and—most importantly—aligned with enterprise-wide governance principles.
However, the primary challenge is no longer technical, but organizational. Security and mainframe teams often operate in disconnected silos, with separate budgets, policies, and even reporting structures. Mainframe admins may not be invited to the same security-planning meetings, generating both knowledge and accountability gaps. Experts agree this must change. Zero Trust, now widely regarded as the gold standard for modern security, requires every asset—legacy or otherwise—to be continuously authenticated, monitored, and treated as a potential breach pathway.
Emerging solutions bring promise. Agentless microsegmentation, for instance, allows organizations to isolate and monitor mainframes without deploying intrusive agents on unsupported platforms. Visual analytics and robust east-west traffic monitoring provide unprecedented visibility into legacy communication paths, while policy engines built around Zero Trust principles allow granular control over network flows and user privileges. These innovations align closely with regulatory expectations, audit requirements, and real-world best practices for risk reduction.
For boards and C-suites, the message is simple: mainframes may be invisible beneath the surface, but so are icebergs. What you cannot see—or choose not to prioritize—can still sink the ship.
In practical terms, this means appointing clear ownership for mainframe security, investing in modern IAM integration, and prioritizing continuous education and accountability. As the era of IAM exceptions rapidly closes, the time for organizational and technical reckoning is now—because, as history continually reminds us, legacy does not excuse liability. It magnifies it.
Source: SC Media Mainframe security faces reckoning as IAM blind spots collide with new compliance mandates
The Mainframe as ‘Someone Else’s Problem’
Despite mounting cybersecurity threats, the world of the mainframe has often been an afterthought for corporate security architects, who frequently assume that all critical infrastructure is protected by a unified IAM strategy. In reality, mainframe administrators have long maintained separate access controls and workflows—sometimes rooted in organizational silos, sometimes in the technical inertia associated with deeply entrenched legacy systems. This practice is not only outdated, but increasingly dangerous, as regulatory frameworks now expand their scope from “where data is stored” to “what data is protected”—obliterating old lines of convenience or exception.Barbara Ballard, Principal Product Manager for Host Connectivity at Rocket Software, put it succinctly: “Just because it’s buried in a data center doesn’t mean it’s out of scope. Regulations don’t care what kind of box it runs on. They care that it contains sensitive data.” Her warning underscores a troubling reality—security leaders can no longer absolve themselves of responsibility for mainframe environments. As compliance and threat pressure mounts, this organizational inertia must yield to a more holistic, enterprise-wide strategy.
The Regulatory Reckoning: MFA Mandates and Scope Expansion
The regulatory environment has shifted dramatically. Frameworks like PCI DSS 4.0, the Digital Operational Resilience Act (DORA) in the European Union, and various U.S. state mandates—from New York’s cybersecurity requirements to the updated Gramm-Leach-Bliley Act—now demand consistent access controls and strong authentication for all systems housing sensitive data, regardless of platform. This explicitly brings mainframes under the purview of modern IAM mandates, ending the era where they could be regarded as “special cases” or carved out by exception.The implications are profound. Many mainframe environments still rely on little more than usernames and passwords for access, or—at best—bolt-on MFA systems that are disconnected from the company’s primary IAM platforms. These workarounds create both end-user friction and compliance nightmares. More critically, they introduce potential loopholes that sophisticated adversaries are increasingly adept at exploiting.
Auditors, meanwhile, are no longer satisfied with paper exceptions or trust in the inherent “hardened” nature of mainframes. Given the number and severity of real-world breaches resulting from legacy system exposures (see: NotPetya, Colonial Pipeline, WannaCry), security teams are now expected to demonstrate, in detail, how access to mainframes is controlled, monitored, and—most importantly—aligned with enterprise-wide governance principles.
Bridging the Mainframe–IAM Divide: Technical and Cultural Solutions
Recognizing this convergence, vendors like Rocket Software are actively closing the gap by developing connectors that allow mainframe authentication to flow through enterprise IAM solutions. These integrations commonly rely on industry standards such as SAML (Security Assertion Markup Language) and OpenID Connect (OIDC), enabling users to authenticate through platforms like Okta or Azure AD before being passed into mainframe applications. The advantage is clear: mainframe credentials can now be governed by the same RBAC policies, conditional access, and MFA requirements as the rest of the enterprise stack.However, the primary challenge is no longer technical, but organizational. Security and mainframe teams often operate in disconnected silos, with separate budgets, policies, and even reporting structures. Mainframe admins may not be invited to the same security-planning meetings, generating both knowledge and accountability gaps. Experts agree this must change. Zero Trust, now widely regarded as the gold standard for modern security, requires every asset—legacy or otherwise—to be continuously authenticated, monitored, and treated as a potential breach pathway.
Emerging solutions bring promise. Agentless microsegmentation, for instance, allows organizations to isolate and monitor mainframes without deploying intrusive agents on unsupported platforms. Visual analytics and robust east-west traffic monitoring provide unprecedented visibility into legacy communication paths, while policy engines built around Zero Trust principles allow granular control over network flows and user privileges. These innovations align closely with regulatory expectations, audit requirements, and real-world best practices for risk reduction.
The Critical Strengths of a Unified Approach
- End-to-End Visibility: Integrated IAM enables continuous observability across the entire stack, revealing shadow users, orphaned credentials, or unmonitored access points that may otherwise go undetected.
- Consistent Policy Enforcement: By treating the mainframe as just another high-value system, organizations can ensure that MFA, RBAC, and account lifecycle policies are universally applied.
- Regulatory Alignment: Unified IAM platforms make it easier to demonstrate compliance with GDPR, PCI DSS, DORA, and sector-specific mandates, reducing the risk of fines and reputational damage.
- Measurable Risk Reduction: Microsegmentation and Zero Trust control frameworks limit the blast radius of an incident and help reduce both mean time to detect (MTTD) and mean time to respond (MTTR).
- Streamlined User Experience: SSO and harmonized MFA across all systems (Windows, cloud, and mainframe) reduce user friction and minimize risky workarounds or ad-hoc access paths.
Notable Challenges and Persistent Risks
Yet, even this modern approach comes with caveats. It is crucial to acknowledge these potential pitfalls:Residual Attack Surface
No technical control can compensate for the outright lack of vendor patches or for zero-day vulnerabilities targeting unpatchable legacy systems. Even compartmentalized, microsegmented environments are at risk if attackers compromise a privileged account or exploit internal dependencies before detection.Complexity and Configuration Drift
Layered, compensatory controls—especially those bolted on top of legacy systems—can become difficult to manage at scale. Over time, misconfigured rules, drifting policies, or lack of documentation may introduce blind spots or create audit failures. Moreover, integration projects sometimes falter in the face of undocumented business logic or operational dependencies woven deep into mainframe workflows.Organizational Inertia
Perhaps the greatest risk is cultural. If security is still perceived as “someone else’s responsibility,” or if legacy teams resist changes that appear to threaten established workflows, the entire enterprise remains exposed. As frameworks like Zero Trust mature, it becomes more critical than ever to foster shared accountability between infrastructure, security, and compliance stakeholders.False Sense of Security
It’s dangerously easy to believe that tools and “best practices” are enough. Yet, without the basics—comprehensive asset inventories, rigorous user training, routine policy reviews, and strong incident response—organizations may find themselves the victims of their own overconfidence. Human error, credential reuse, social engineering, and other perennial threats remain as relevant for mainframe security as for any other IT domain.Dependency Hell
Legacy environments are notorious for their tangled web of dependencies. Aggressive segmentation or policy changes, if not mapped carefully, risk breaking business-critical operations or disrupting production processes. This makes remediation and modernization efforts more challenging and stressful, especially in regulated industries with little room for unplanned downtime.The Road to Future-Ready Mainframe Security: Practical Steps
Every organization’s journey will look different, but industry experts and successful security leaders agree on the need for a pragmatic, layered strategy:1. Accept Legacy as a Permanent Reality
It is a costly delusion to wait for “rip-and-replace” modernization. Legacy systems—mainframes, OT, or unsupported Windows—are here for the long term. Organizations must plan for their secure operation, integrating risk mitigation and isolation as standard operating procedures.2. Prioritize, Segment, and Harden
Start with a thorough asset inventory. Segment legacy assets by risk profile and exposure. Place the highest-value assets in tightly controlled enclaves, limiting communication only to what is absolutely necessary. Compensatory controls such as access control lists, robust monitoring, and limited remote management further strengthen the defensive posture.3. Layer Controls at Every Level
Least privilege should be standard. Both user and service accounts must be reviewed and restricted to only what’s strictly necessary. Layer technical controls (IAM, segmentation), robust security training, and strong incident response plans to build resilience—expect breaches, and prepare to contain and recover rapidly.4. Embrace Zero Trust and Agentless Solutions
Where possible, pursue agentless technologies for visibility and network control. AI-driven anomaly detection, user/entity behavioral analytics, and policy-based enforcement platforms modernize security without requiring invasive changes to mainframe code or operations.5. Document, Audit, and Iterate
Continuous improvement is essential. Regular audits, policy reviews, and automated configuration management close the gap between intent and reality, supporting both internal and external compliance requirements.A Call to Action: Mainframe Security as Enterprise Security
Organizations that treat mainframe security as a distinct, isolated discipline are not just missing out on efficiency gains—they are risking compliance penalties, business disruption, and reputational loss in the event of a breach. Security leaders must act now, working across technical and organizational silos to build a truly unified security framework—one that takes legacy systems as seriously as new cloud assets.For boards and C-suites, the message is simple: mainframes may be invisible beneath the surface, but so are icebergs. What you cannot see—or choose not to prioritize—can still sink the ship.
Conclusion: Defending the Past, Securing the Future
Mainframe environments are no longer “out of scope.” As attackers grow more sophisticated, and as the regulatory noose tightens, organizations must abandon the myth of “safe by obscurity.” The future belongs to those who can make legacy and modern, on-prem and cloud, speak the same language of security and accountability. By embracing integrated IAM, Zero Trust, persistent audit, and relentless cross-functional collaboration, enterprises can secure not just their newest assets, but the aging core upon which their digital futures rest. Failure to act is no longer mere technical debt—it’s an existential risk.In practical terms, this means appointing clear ownership for mainframe security, investing in modern IAM integration, and prioritizing continuous education and accountability. As the era of IAM exceptions rapidly closes, the time for organizational and technical reckoning is now—because, as history continually reminds us, legacy does not excuse liability. It magnifies it.
Source: SC Media Mainframe security faces reckoning as IAM blind spots collide with new compliance mandates
