Zero-Days in 2025: Why exploits are being chained faster than ever

Why Are Zero-Day Exploits Increasing in 2025?

In 2025, the cybersecurity landscape is witnessing a sharp escalation in zero-day vulnerability exploitation. According to industry trackers, over 30 zero-days have already been publicly disclosed in Q1 2025 alone, putting the year on pace to surpass 100 zero-day cases by year-end. This pace would mark a new high, outstripping both 2023 and 2024, and reflects a broader transformation in how threat actors identify, weaponize, and deploy vulnerabilities.

What’s changed isn’t just volume—it’s velocity. Exploits are now being chained within days, sometimes hours, of disclosure. The average time-to-exploit for high-value systems has shrunk dramatically, driven by automated exploit development, AI-enabled fuzzing platforms, and the rise of weaponized proof-of-concept repositories. In this new climate, organizations can no longer afford the luxury of quarterly patch cycles or delayed CVE impact assessments. Zero-day attacks are increasingly coordinated, targeted, and designed to break through layered defenses in ways that were previously rare.

How Is AI Accelerating the Discovery and Weaponization of Vulnerabilities?

A critical factor behind the acceleration of zero-day exploitation is the use of AI to automate the most labor-intensive parts of vulnerability research. What once required expert manual reverse engineering is now handled by large language models trained on assembly syntax, fuzzing logs, and control flow logic. These AI tools simulate billions of possible states and inputs, searching for crash conditions and logic misfires across production binaries.

Security research teams at Microsoft and Google Project Zero have already adopted these tools for proactive detection—but attackers have them too. In offensive operations, AI fuzzers can ingest a recently patched binary, diff it against prior versions, and identify which routine was changed and whether it can be exploited. These tools don’t just find bugs; they model exploitability. By scoring conditions for remote code execution, sandbox escape, or kernel elevation, they’re dramatically shrinking the exploit development lifecycle.

This tech shift has real-world consequences. In May 2025, Microsoft patched five actively exploited zero-days, including CVE-2025-30397, a scripting engine flaw under live exploitation before the update shipped. Researchers believe the exploit emerged from an AI-driven patch diffing system that spotted the fix, reconstructed the bug, and published a working payload within 48 hours.

Why Are Attackers Chaining Multiple CVEs Instead of Using One?

The modern attacker rarely relies on a single CVE. Instead, they chain together multiple medium or low-severity bugs into multi-step attacks. These chains typically begin with an information disclosure or logic flaw, pivot through an authentication bypass, and culminate in code execution or privilege escalation.

In May 2025 alone, CrowdStrike documented multiple incidents where adversaries chained together elevation-of-privilege bugs in the Windows Common Log File System (CVE-2025-32701 and CVE-2025-32706) with unpatched remote execution flaws in exposed web services. Attackers breached hardened environments not by breaking through the front door, but by linking smaller flaws into sophisticated lateral movements.

The trend is clear: software sprawl, API interdependence, and third-party plugin ecosystems have made chained exploits more viable than ever. Every interface, sandbox, and microservice is now a potential weak link. The rise of federated identity and multi-tenant cloud platforms only increases the surface area for these attacks.

Which Enterprise Platforms Are Most Vulnerable to Zero-Day Chains?

Enterprise-grade software and platforms have become primary targets. Google’s Threat Analysis Group recently noted that 44% of zero-days exploited in 2024 targeted enterprise platforms—a trend continuing strongly into 2025. Security and networking software is especially at risk, as attackers know these systems often sit deep in infrastructure with elevated privileges and broad access scopes.

The exploitation of CVE-2025-31324 in SAP NetWeaver exemplifies this. The vulnerability allowed unauthenticated users to upload malicious files and execute arbitrary code. Despite SAP releasing an emergency patch, multiple customers were compromised in targeted campaigns within days. This was not a case of overlooked maintenance—it was a calculated exploit against one of the most secure enterprise application stacks in the world.

These incidents are a warning. Even highly mature platforms are not immune. As software ecosystems become more integrated and distributed, attackers are exploiting not just application flaws but architectural assumptions that were never intended to be part of the public attack surface.

How Are Investors and Security Buyers Responding to Chained Exploits?

Across both enterprise buyers and institutional investors, exploit chaining is now a red flag that influences product evaluation, contract renewals, and market trust. Security leaders are demanding that vendors show not just vulnerability responsiveness, but actual architectural resistance to chaining.

Security vendors like Palo Alto Networks, SentinelOne, and CrowdStrike are positioning their detection stacks as anti-chaining solutions. Their platforms advertise behavioral analytics, runtime memory protection, and chain-aware telemetry correlation to identify multi-stage attacks before damage occurs. These capabilities are now key differentiators in enterprise RFPs and budget planning cycles.

Investor interest is also growing. In Q1 2025 earnings calls, several cybersecurity companies emphasized their zero-day research capabilities and exploit detection pipelines. Shareholder reports from vendors like Zscaler and Check Point noted increased customer demand for protection against chained exploits, especially in sectors like defense, critical infrastructure, and healthcare.

What Role Do Regulations and Cyber Insurers Play in Zero-Day Preparedness?

Governments are reacting too. The U.S. Executive Order on Improving the Nation’s Cybersecurity now mandates that federal vendors provide a Software Bill of Materials (SBOM) and maintain zero-day readiness programs. The EU’s Cyber Resilience Act pushes for rapid CVE disclosure, chain impact assessment, and contractual clarity on third-party component responsibilities.

Cyber insurers are adjusting accordingly. Premiums are rising for firms that cannot demonstrate exploit chain risk modeling. Underwriters increasingly require evidence of SBOM management, cloud workload isolation, and continuous runtime monitoring. For buyers, a lack of architectural control over exploit chains is now a quantifiable liability—reflected in both coverage costs and policy exceptions.

How Can Organizations Defend Against Chained Zero-Day Attacks?

To survive the chained zero-day era, organizations must modernize beyond perimeter controls and static patch cycles. They need defense-in-depth models that assume exploitation will happen and design systems to detect, isolate, and limit the blast radius.

This starts with hardening trust boundaries—ensuring that no interface or service trusts unauthenticated input, even internally. Zero trust network models, strong access governance, and API rate limiting are no longer optional. Runtime security controls, including behavior-based EDR and container isolation, are essential.

Equally important is continuous visibility. Organizations should monitor not just system logs, but how software components interact across layers. Chain-aware telemetry analysis, coupled with red teaming against real exploit paths, is becoming a baseline expectation in regulated industries.

In 2025, zero-days aren’t singular events. They’re modular weapons that attackers rapidly combine into multi-step chains—using automation, AI, and the sprawling nature of today’s software systems. The question for CISOs, architects, and policymakers is no longer “how fast can we patch?” but “how well can we contain what we don’t yet know?” In the era of chain-driven zero-day exploitation, resilience is not about perfection. It’s about preparation, segmentation, and the ability to detect abuse before it scales.