New Research Reveals APIs are the Single Most Exploited Attack Surface

Wallarm released The 2026 API ThreatStats Report, a data-driven analysis of API attack telemetry, published vulnerabilities, confirmed exploitation, and API-related breaches disclosed in 2025. The report shows a consistent pattern CISOs can’t afford to treat as “just an AppSec problem” – attackers are successfully exploiting repeatable failures in identity, access control, and exposed interfaces, often at machine speed and massive scale.

New research from @Wallarm reveals APIs are the single most exploited attack surface. Read the report: https://www.wallarm.com/reports/2026-wallarm-api-threatstats-report

APIs dominate vulnerability and exploit reality, not just theory. APIs are the primary focus of vulnerability and exploit concerns, moving beyond theoretical discussions into real-world threats. Wallarm analyzed 67,058 published vulnerabilities from 2025 and found 11,053 (17%) were API-related. In parallel, analysis of CISA KEV additions in 2025 found that 43% were API-related, making APIs the single largest exploited surface in the dataset.

“API security is at the heart of any AI transformation,” said Ivan Novikov, Founder & CEO at Wallarm. “Every AI application or agent interaction is mediated through an API. API security is integral to successful AI adoption, and AI by its very nature has made the consequences of getting it wrong much larger and much more impactful.”

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Key findings from The 2026 API ThreatStats Report

AI security is API security, and the overlap is not subtle. The report found 2,185 AI-related vulnerabilities in 2025, with 786 overlapping API-related vulnerabilities. That means 36% of AI vulnerabilities involve APIs. In exploited vulnerabilities, the pattern persists: 36% of AI-related KEVs also involved an API attack surface.

“Abuse beats bugs” in real-world API attacks. The API ThreatStats Top 10, based on observed attack volume, shows attackers favor logic abuse, trust failures, and resource consumption over traditional code defects. In 2025, Cross-Site Issues moved to the top by attack volume, while Injections remained a high-impact anchor threat, and Broken Access Control continued to enable scalable exploitation.

Agentic AI introduces a new control plane risk: MCP. Model Context Protocol (MCP) emerged as a leading indicator of where API risk is heading. Wallarm identified 315 MCP-related vulnerabilities in 2025, representing 14% of all published AI vulnerabilities. MCP vulnerabilities showed extreme momentum, including 270% growth from Q2 to Q3 in 2025, and were tied to a Top 10 API breach involving thousands of exposed MCP servers.

Most API vulnerabilities are fast, remote, and easy to exploit. Attackers take full advantage of these attributes. The report found 97% of API vulnerabilities can be exploited with a single request, 98% are easy or trivial to exploit, and 99% are remotely exploitable. In 59% of cases, no authentication is required. Traditional security tools that don’t provide real-time blocking fall short in defending against these API attacks.

What this means for CISOs

The report’s breach analysis reinforces that the most damaging incidents are not driven by sophisticated adversaries. They are driven by repeatable gaps in identity handling and exposed API surfaces. In 2025 breach data, AI platforms and tooling accounted for 15% of API-related breaches, tying software as the largest category in the dataset.

For security leaders, the takeaway is direct: improving AI security is about APIs, and improving API security is not about chasing new attack classes. It’s about systematically addressing identity, exposure, and abuse before automation and scale turn familiar weaknesses into material business risk.