Why do third-party identities increase supply chain risk?

Why Third-Party Identities Raise Supply Chain Risk

Third-party identities are risky because they extend trust across organisational boundaries without inheriting the same controls, visibility, or revocation discipline. A supplier account, integration token, or service credential may be created for a narrow business purpose, then quietly persist long after the need changes. That creates an attractive supply chain path: attackers do not always need to breach the primary target if they can compromise the weaker upstream identity first.

This is why NHI Management Group treats third-party identity governance as a core supply chain control, not a vendor-management afterthought. The issue is amplified when organisations rely on static secrets, shared accounts, or manual offboarding. Guidance in the OWASP Non-Human Identity Top 10 and NIST’s NIST Cybersecurity Framework 2.0 both reinforce the same point: trust must be limited, measurable, and revocable. In practice, many security teams discover supplier identities only after a partner compromise or unexpected token reuse has already expanded access.

NHIMG research on the 52 NHI breaches Report shows how often identity sprawl, poor lifecycle control, and secrets exposure contribute to real incidents. The lesson is simple: if a third-party identity can survive the relationship that created it, it can survive into an attack.

How Supply Chain Exposure Happens in Practice

Third-party risk usually emerges through identity mechanics, not just contractual weakness. A vendor may receive API keys for integrations, service principals for automation, or privileged access for support. If those identities are over-scoped, embedded in scripts, or shared across environments, the blast radius becomes much larger than the original business need.

The most common failure patterns are familiar:

• Long-lived secrets that are never rotated, so compromise remains useful for weeks or months.
• Over-permissioned access that grants broad read, write, or admin capability where a narrow task token would do.
• Poor offboarding, where access is removed in the contract but not in the identity plane.
• Weak inventory, where organisations cannot answer which supplier identities exist, what they can reach, or who owns them.

Supply chain incidents often begin in less obvious places than production systems. NHIMG’s Reviewdog GitHub Action supply chain attack and Shai Hulud npm malware campaign illustrate how CI/CD tooling, build pipelines, and package ecosystems can expose secrets that were never meant to leave the trust boundary. The broader trend is visible in the NHIMG-linked The State of Secrets Sprawl 2026, which reports that 64% of valid secrets leaked in 2022 are still valid and exploitable today.

Operationally, the answer is to treat third-party access as just-in-time, scoped, and continuously re-evaluated. Short-lived credentials, strong ownership, automated revocation, and periodic attestations are all part of the control stack. These controls tend to break down when suppliers need persistent machine-to-machine access across many environments because revocation, token rotation, and exception handling become hard to coordinate at scale.

Where the Standard Answer Breaks Down

Tighter supplier access controls often increase integration overhead, requiring organisations to balance friction against assurance. That tradeoff is real, especially for managed service providers, software vendors, and outsourced operations teams that need repeatable access across multiple tenants.

Best practice is evolving, but there is no universal standard for every third-party scenario. Some relationships justify ephemeral access and per-task approval; others require standing access with compensating controls such as network segmentation, session recording, and high-frequency rotation. The key is to avoid treating all vendors as equal risk. A build partner with repository write access is not the same as a helpdesk tool with read-only telemetry.

There is also a practical reporting gap. Many organisations can name their top suppliers but cannot map every token, key, certificate, and service account those suppliers use. That gap becomes more dangerous when a third party subcontracts to another provider, because the trust chain extends beyond the original contract. Current guidance suggests mapping the full chain of custody for identities, not just the legal relationship. NHIMG’s Ultimate Guide to NHIs — Key Challenges and Risks and Top 10 NHI Issues are useful references when building that inventory discipline.

In short, supply chain risk rises whenever third-party identities are allowed to outlive their purpose, outscope their mandate, or outpace the organisation’s ability to revoke them.

Related resources from NHI Mgmt Group

• Why do overpermissioned third-party integrations increase supply chain risk?
• Why do third-party credentials increase supply chain risk?
• How should security teams manage third-party non-human identities in supply chain environments?
• Why do automated build identities increase supply chain compromise risk?