Why do service account and maintainer tokens increase supply-chain risk?

Why This Matters for Security Teams

service account and maintainer tokens are not just “machine credentials.” They are often the trust bridge between code, package registries, build systems, source control, and cloud control planes. When one token can publish artifacts, approve workflows, or query production systems, compromise becomes a supply-chain event rather than a single account incident. Current guidance from the OWASP Non-Human Identity Top 10 treats over-privileged and long-lived NHI credentials as a core risk pattern.

That risk is amplified by secret sprawl. NHIMG’s The State of Secrets Sprawl 2026 found that 59% of compromised machines in a major 2025 supply chain attack were CI/CD runners rather than personal workstations, showing how trust collapses through automation paths that teams often overlook. The problem is not only theft, but reuse: a single token may authenticate across systems that were never designed to fail together. In practice, many security teams encounter this only after a package publish, pipeline compromise, or data extraction has already occurred, rather than through intentional token lifecycle control.

How It Works in Practice

Maintainer tokens and service account tokens increase supply-chain risk because they usually carry broad, reusable authority with weak context checks. If a token is stored in a build job, leaked from a developer workstation, or inherited by a downstream automation step, the attacker does not need to break each control separately. One credential can be enough to tamper with source, sign or publish packages, change deployment settings, or pivot into cloud APIs.

Practical defence starts by reducing what the token can do and how long it lives. Security teams should prefer short-lived credentials, just-in-time issuance, and workload identity over static shared secrets. The NIST Cybersecurity Framework 2.0 reinforces continuous protection and access governance, while NHIMG’s Guide to the Secret Sprawl Challenge highlights how quickly exposed secrets propagate across repositories and automation tooling.

• Bind tokens to a single workload, environment, or pipeline stage.
• Issue tokens per task and revoke them on completion.
• Separate publish, deploy, and read-only permissions instead of using one maintainer token for all actions.
• Audit who can mint, store, and rotate tokens in CI/CD, package managers, and cloud consoles.

In mature environments, token use should be evaluated at runtime against policy, not assumed safe because it belongs to a known service account. These controls tend to break down in legacy build systems that cannot enforce ephemeral identity, where long-lived tokens are embedded in scripts, runners, or third-party integrations.

Common Variations and Edge Cases

Tighter token controls often increase operational overhead, requiring organisations to balance delivery speed against blast-radius reduction. That tradeoff is especially visible in release engineering, where maintainers want frictionless publishing and automation teams want narrow, revocable access. Best practice is evolving, but there is no universal standard for which token classes should be fully ephemeral versus tightly rotated and monitored.

Some environments can tolerate limited-service tokens if they are constrained to a single repo, package namespace, or non-production system. Others, such as high-volume CI/CD platforms and multi-tenant developer tooling, should assume token compromise is inevitable and design for rapid containment. NHIMG’s 52 NHI Breaches Analysis shows how often compromised non-human identities become persistence mechanisms, not one-off access keys. For teams formalising governance, the OWASP Non-Human Identity Top 10 is the clearest baseline for lifecycle, least privilege, and secret handling expectations.

Teams also need to account for maintainer tokens used outside code repositories, such as in chat ops, ticketing, and release bots. Those pathways can be harder to inventory than CI variables, which means detection often lags behind exposure. The hardest failures appear when a token is both trusted and convenient, because that combination encourages reuse across systems that were never meant to share a single point of compromise.

Related resources from NHI Mgmt Group

• Why do service account tokens increase lateral movement risk?
• How do attackers turn a supply-chain incident into wider NHI compromise?
• How should teams respond when a service account token is exposed?
• Why do AI coding agents increase supply-chain risk?