The mainframe remains the system of record for many of the world’s largest organizations and some of their most critical data. As of 2025, 71% of Fortune 500 companies still use mainframes, and nearly 97% of banks worldwide rely on IBM mainframe products.
Yet many security programs continue to treat the mainframe differently from the rest of the enterprise. Many organizations still assume the mainframe is inherently secure.
Mainframes are designed with strong security controls. But strong controls alone are not enough. Like any critical enterprise system, the mainframe requires continuous verification to ensure those controls are working as intended.
Risk can exist anywhere. An overlooked configuration in a z/OS environment can create opportunities for unauthorized access to sensitive systems and data. As the time between vulnerability discovery and exploitation continues to shrink, organizations need greater visibility into risk across the enterprise—including the mainframe.
Myth #1: Mainframes are unbreachable
Can mainframes be breached? Although mainframes are designed with robust security features, no technology platform is immune to risk. The reality is simple: attackers go where the valuable data is stored.
The mainframe isn’t isolated from the rest of the enterprise. Mainframes routinely process millions of transactions per day, and high-end systems can process over a million transactions per second in certain workloads. Mainframes are estimated to handle a substantial share of the world’s transactional workloads and credit card processing.
As organizations modernize and connect systems across environments, visibility into potential exposure becomes just as important on z/OS as it is everywhere else. Attackers follow opportunity. Wherever valuable data and business-critical assets reside, flaws will attract attention. As organizations adopt hybrid architectures, the number of interconnected systems continues to grow, making identity governance and access assurance increasingly important.
The solution is to treat the mainframe as part of the enterprise attack surface and manage risk there the same way you do everywhere else. Mainframe security requires the same continuous visibility organizations expect across the rest of the enterprise.
Myth #2: Specialized systems are too complex for attackers
How is AI changing vulnerability discovery? In the past, surfacing exposures on the mainframe required deep expertise that relatively few people had. That complexity made these environments harder to analyze.
Recent attention around Mythos, Anthropic’s highly restricted security research model, has sparked debate about AI’s role in cybersecurity. If security flaws become dramatically easier to find, organizations may have less time to identify and remediate weaknesses before others discover them.
The important point isn’t Mythos itself. It’s that identifying exploitable weaknesses is becoming faster, cheaper, and easier.
Organizations can no longer assume that complexity will keep attackers at bay. Mainframe security strategies should account for a future in which gaps are discovered faster than ever before.
That requires greater visibility into the z/OS environment and the risks it may pose. Continuous analysis helps organizations uncover potential weaknesses early, and the sooner security teams can detect security gaps, the more time they have to fix them.
Myth #3: Annual security assessments are sufficient
Why is continuous vulnerability analysis important for mainframe security? Many organizations still rely on periodic configuration assessments, even though today’s threats move much faster than they did when those processes were created. Today’s mainframe environments are constantly evolving, and new weaknesses can emerge between checkpoints long before the next scheduled assessment.
Security teams need ongoing visibility into risk, not occasional snapshots. That’s why continuous vulnerability analysis has become a critical component of modern mainframe management, helping teams identify and remediate weaknesses before they escalate into incidents.
Organizations have long benefited from the security architecture and integrity of mainframe environments. As vulnerability discovery becomes more efficient, maintaining visibility into those environments becomes increasingly important. Rocket Mainframe Security solutions help organizations build continuous visibility across their z/OS environments and act on it early.
For organizations seeking greater visibility across their z/OS environment, Rocket z/Assure Vulnerability Analysis Program (VAP) helps identify weaknesses within authorized programs and supports ongoing remediation efforts. VAP helps security teams identify security gaps in software earlier, reducing risk before they affect critical systems.
What continuous mainframe security requires
- Visibility into sensitivities across the z/OS environment
- Ongoing validation of security controls
- Integration with enterprise risk management processes
- Faster identification and remediation of emerging weaknesses
- Continuous assessment rather than periodic review
The future of mainframe security requires continuous vulnerability analysis
Security weaknesses can exist anywhere in the enterprise, and they are being discovered faster than ever before. Detecting risk is getting easier, and organizations should plan accordingly.
This is where continuous vulnerability analysis becomes essential. Point-in-time assessments provide a snapshot of risk, while continuous risk analysis helps organizations maintain visibility as systems change.
The broader lesson from advanced AI models like Mythos is that vulnerability discovery is accelerating. For organizations that depend on the mainframe, visibility becomes more important as the time between discovery and exploitation shrinks. Organizations that adopt continuous analysis across critical environments will be better positioned to identify and address risk before attackers do.