TL;DR: API sprawl is creating hidden endpoints, inconsistent controls, and compliance risk across cloud-native environments, with Salt Security citing that over 63% of organisations saw incidents from unmonitored or inadequately secured APIs in 2024. The governance problem is no longer discovery alone. It is lifecycle control, access control, and continuous enforcement across every API that can expose data or credentials.
At a glance
What this is: API sprawl is multiplying unmanaged endpoints across cloud-native estates, and Salt argues that the resulting blind spots are making traditional security and governance practices fail.
Why it matters: For IAM and security teams, the issue is not just API volume but enforcement scope, because unmanaged APIs often become uncontrolled access paths for data, tokens, and sensitive business flows.
By the numbers:
- Over 63% of organisations experienced security incidents due to unmonitored or inadequately secured APIs in 2024.
Context
API sprawl is the accumulation of too many APIs across teams, environments, and services for central governance to keep up. In practice, the risk is not simply having more interfaces. It is that each new endpoint can introduce a new authentication path, a new data flow, and a new place where access control can drift from policy.
The governance gap becomes sharper in cloud-native and third-party integration-heavy environments, where APIs are created quickly and often maintained inconsistently. That creates direct identity and access implications because API keys, tokens, service accounts, and delegated permissions frequently sit behind those endpoints. When API inventory and lifecycle control lag behind development, the organisation loses its ability to say who can reach what, and when.
The pattern is now typical rather than exceptional for modern digital estates. Organisations that treat API management as a separate technical issue rather than an identity and control problem usually discover the gap only after exposure or incident response begins.
Key questions
Q: What breaks when API sprawl is not controlled centrally?
A: When API sprawl is unmanaged, teams lose visibility into where data flows, which credentials remain active, and which endpoints are still live. That makes consistent authentication, logging, and remediation impossible at scale. The practical failure is not just more endpoints, but more undocumented access paths that attackers can discover before defenders can govern them.
Q: Why do unmanaged APIs increase identity and access risk?
A: Because APIs are often accessed by service accounts, tokens, and application credentials that never pass through the same review discipline as human users. When the API estate is incomplete, teams cannot reliably confirm who or what is authorised to call which function. That weakens least privilege and makes excess access harder to detect.
Q: What are the signs that API governance is failing at runtime?
A: Common signs include undocumented endpoints, duplicated ownership, inconsistent responses, rising retry loops, and frequent discovery of APIs that are not in the catalogue. Those signals show that the live estate and the formal control model no longer match. Once that happens, security and reliability teams are managing assumptions instead of actual behaviour.
Q: What is the difference between API discovery and API governance?
A: API discovery finds what exists, while API governance decides who may use it, how it may be accessed, and when that access must be removed. Discovery is the visibility layer; governance is the control layer. Organisations need both, because you cannot enforce policy on interfaces you have not found.
Technical breakdown
Why API sprawl creates hidden access paths
Every API endpoint is a potential control point, but also a potential bypass if it is not inventoried, authenticated, and monitored consistently. In distributed environments, teams often create APIs faster than security can classify them, so shadow and orphaned endpoints remain reachable long after the business owner has moved on. That turns API governance into a visibility problem first and an enforcement problem second. The real risk is not just exposure of a single interface, but the accumulation of unmanaged paths that break the assumption that the security team knows the full attack surface.
Practical implication: maintain a continuously updated API inventory and treat unknown endpoints as unmanaged access paths until proven otherwise.
How inconsistent authentication and authorisation weaken API estates
API sprawl often produces mixed control patterns across the same organisation. Some services use robust token-based controls, while older or locally managed APIs still rely on basic API keys or weak authentication. That inconsistency creates uneven trust boundaries and increases the chance that an attacker can move from a lightly governed endpoint to sensitive data or business flows. For IAM teams, the key issue is that access control is no longer central if each business unit can define its own API enforcement model. The control plane becomes fragmented, and policy exceptions multiply.
Practical implication: standardise authentication, authorisation, and encryption requirements across all APIs, including legacy and partner-facing services.
Shadow and zombie APIs are a lifecycle control failure
Shadow APIs are endpoints the organisation never properly recorded, while zombie APIs are those that were once legitimate but were never retired. Both are dangerous because they persist outside normal change and review processes, which means they can remain active with stale credentials, outdated permissions, or missing anti-abuse controls. This is where API governance intersects directly with NHI management, since machine credentials often outlive the team or project that created them. The failure is not merely technical debt. It is a lifecycle breakdown that leaves access paths open after their business purpose has ended.
Practical implication: tie API creation, ownership, review, and decommissioning to formal lifecycle controls so orphaned endpoints cannot remain exposed.
Threat narrative
Attacker objective: The attacker aims to exploit unmanaged API access paths to retrieve sensitive data or abuse business workflows without being detected.
- Entry occurs through exposed or undocumented API endpoints that are not covered by normal monitoring or governance.
- Credential or access abuse follows when weak API keys, tokens, or permissive authorisation let the attacker query data or invoke business functions.
- Impact is realised through data exposure, compliance failure, or unauthorised access to sensitive business flows across connected services.
Breaches seen in the wild
- Salesloft OAuth token breach: hackers stole OAuth tokens to access Salesforce data via Salesloft.
- Klue OAuth Supply Chain Breach: OAuth tokens compromised in Klue integration breach affecting 700+ organisations via Salesforce data access chain.
Read and download The State of NHI & AI Agent Breach Report 2026, covering 200+ breaches impacting Non-Human Identities including AI Agents.
NHI Mgmt Group analysis
API sprawl is now an identity governance problem as much as a security architecture problem. When every team can create, keep, and modify API access paths independently, the organisation loses lifecycle control over machine-facing entry points. That matters because API keys, tokens, and service credentials often outlive the business need that created them. Practitioners should treat API governance as an access governance discipline, not just an inventory exercise.
Shadow and zombie APIs create a standing-privilege pattern for machines. The endpoint may be forgotten, but the access path remains live, which means the exposure window stays open indefinitely. This is the same governance failure seen in other non-human identity problems, where an asset continues to authenticate after its owner has lost sight of it. Security teams need to view unmanaged APIs as credential-bearing assets with a lifecycle, not as dormant code.
Centralised API enforcement is becoming the minimum viable control model. The article shows that fragmented standards across business units lead directly to inconsistent authentication, authorisation, and compliance outcomes. A named concept here is API lifecycle drift: the gap between API creation and API retirement during which policy, ownership, and enforcement fall out of sync. The practical conclusion is that organisations should align API governance with access reviews, ownership, and decommissioning controls.
Regulatory exposure follows weak API control because data flow visibility is the control surface, not a side effect. Once APIs proliferate across cloud and partner integrations, it becomes harder to prove where personal or transactional data moves, which directly affects auditability and accountability. That is why this problem sits at the intersection of IAM, data governance, and operational control. Practitioners should treat undocumented endpoints as compliance risks, not merely technical debt.
From our research library:
- 92% of organisations expose NHIs to third parties, raising concerns about supply chain security, according to the Ultimate Guide to NHIs.
- Read next: SaaS-to-SaaS and OAuth App Governance Guide
What this signals
API lifecycle drift: the gap between endpoint creation and formal retirement is where most governance failures accumulate, because security teams lose track of ownership, authentication pattern, and business purpose. The practical response is to bring APIs into the same lifecycle discipline used for other high-risk access paths, including review, ownership, and decommissioning.
Organisations that still manage APIs as a developer convenience rather than a governed access surface will keep inheriting shadow endpoints, stale tokens, and inconsistent policy enforcement. That makes API security a board-relevant control issue, not just a technical operations concern.
For practitioners
- Implement continuous API discovery Continuously scan cloud, SaaS, and internal environments for undocumented APIs, then compare them with the authoritative service inventory so shadow endpoints can be investigated quickly.
- Standardise authentication and authorisation Require one baseline for API authentication, token handling, encryption, and access control across all teams so older endpoints do not retain weaker policies than current services.
- Tie APIs to explicit owners Assign a named owner for every API, including partner and internal interfaces, so review, incident response, and retirement decisions always have an accountable team.
- Retire orphaned endpoints on a fixed lifecycle Use decommissioning rules that remove APIs no longer tied to an active business purpose, especially where the endpoint still accepts tokens or exposes data flows.
Key takeaways
- API sprawl creates unmanaged access paths that can outlive the systems and teams that created them.
- The biggest failure is not volume alone, but inconsistent authentication, fragmented ownership, and weak retirement of old endpoints.
- Treat API inventory, access policy, and decommissioning as one lifecycle control problem, not three separate tasks.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP API Security Top 10 and MITRE ATT&CK address the attack and risk surface, while CIS Controls v8 and NIST CSF 2.0 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP API Security Top 10 | API9 — Improper Inventory Management | The article centres on undiscovered and undocumented APIs that security teams cannot track. |
| API2 — Broken Authentication | Weak or inconsistent API authentication is one of the core failures described here. | |
| API8 — Security Misconfiguration | The article highlights uneven security standards and misconfigured protections across APIs. | |
| Recommendation — Map every live API to API9 and block deployment of endpoints that are not inventoried. Standardise API2 controls so every endpoint uses approved authentication and rejects legacy bypass paths. Use API8 to enforce consistent security baselines across all API environments and teams. | ||
| CIS Controls v8 | CIS-5 — Account Management | Orphaned APIs and stale machine access indicate weak lifecycle and account governance. |
| Recommendation — Apply CIS-5 to remove stale API owners, credentials, and access paths when services are retired. | ||
| NIST CSF 2.0 | PR.AA-05 — Access Permissions, Entitlements and Authorizations | The article is about governing who and what can reach API endpoints consistently. |
| Recommendation — Use PR.AA-05 to enforce consistent API authorisations across cloud, partner, and internal services. | ||
| MITRE ATT&CK | TA0006;TA0008 — Credential Access; Lateral Movement | Exposed APIs can provide attackers with credential-bearing entry points and paths to broader access. |
| Recommendation — Map exposed API endpoints to TA0006 and TA0008 during threat hunting and incident scoping. | ||
Key terms
- API sprawl: API sprawl is the uncontrolled growth of application programming interfaces across systems, teams, and environments. It creates duplicated endpoints, inconsistent authentication, weak ownership, and hidden data exposure. In security terms, API sprawl expands the attack surface, complicates inventory and governance, and makes policy enforcement, monitoring, and lifecycle control harder to sustain.
- Shadow API: An API endpoint that exists in production but is not fully known, reviewed, or governed by the security programme. Shadow APIs often emerge through fast delivery, copy-paste development, or overlooked internal routes, and they create untracked exposure because they sit outside inventory, policy, and ownership processes.
- Zombie API: A zombie API is a deprecated or abandoned interface that remains accessible after the organisation believes it should be retired. It is risky because old permissions, secrets, or backend trust can survive the business purpose, turning legacy access into an active exposure.
- API Lifecycle Governance: API Lifecycle Governance is the discipline of controlling an API from design through retirement. It defines how APIs are approved, versioned, documented, secured, monitored, and decommissioned. In practice, it aligns ownership, authentication, authorization, logging, change control, and risk review so APIs remain trustworthy across their full operational life.
Deepen your knowledge
NHI Foundation Level course, the industry's only accredited NHI security programme, covers NHI governance, machine identity security, and secrets management. It helps practitioners connect access lifecycle control to the broader identity risks that modern API estates create.
Published by the NHIMG editorial team on August 2, 2026.
Updated on October 12, 2026.
NHI Mgmt Group, the independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org