Token security needs zero trust to stop stolen token abuse

At a glance

What this is: This is an analysis of token security through a Zero Trust lens, arguing that valid tokens alone are not enough when tokens can be stolen, replayed, or abused.

Why it matters: It matters because IAM teams must move beyond static token validation and make access decisions that account for device, network, and behavioural context across human and machine sessions.

By the numbers:

• 64% of valid secrets leaked in 2022 are still valid and exploitable today, proving that detection alone is not enough without automated revocation.
• 28.65 million new hardcoded secrets were detected in public GitHub commits in 2025 alone, a 34% year-over-year increase and the largest single-year jump ever recorded.
• When AWS credentials are exposed publicly, attackers attempt access within an average of 17 minutes and as quickly as 9 minutes in some cases.

👉 Read SecureAuth's analysis of zero trust token security and session trust

Context

Token security is often treated as a validation problem, but the real issue is whether a presented token still deserves trust in the moment it is used. In modern identity programmes, that question matters for human sessions, service accounts, and application-to-application access because a stolen token can look legitimate long after the original context has changed.

The article frames Zero Trust token handling as a response to that gap: verify every presentation, bind the token to the current context, and keep sessions short-lived. That approach fits identity governance better than legacy assumptions that a signed token equals an authorised actor, especially when tokens can be replayed from a different device or network.

For practitioners, the issue is not whether token-based authentication works, but whether the surrounding control plane can detect when the token no longer matches the risk state. That is a typical problem in mature IAM environments, not an edge case.

Key questions

Q: What breaks when token signatures are not validated with a strong cryptographic algorithm?

A: If token signatures are not validated properly, attackers may forge tokens, alter claims, or bypass access controls. That creates a direct path to unauthorized access in zero trust environments. The failure is not only technical validation, but also architectural trust, because downstream systems may accept tokens that should never have been trusted.

Q: Why do stolen tokens remain dangerous even when authentication is strong?

A: Strong authentication only helps at the point of issuance. After a token is copied, the attacker can often reuse it without knowing the original password or MFA factor, especially if the session is long-lived and not bound to context. The risk comes from the token's reuse value, not from how hard it was to obtain.

Q: How should security teams decide when to step up or deny token use?

A: Use step-up or denial when the token is presented from a different device, a different network, or a behavioural pattern that does not match the original session. The decision should be tied to the current risk state, not to token validity alone. That keeps legitimate work moving while making replay much less profitable.

Q: Should organisations use short-lived tokens or continuous refresh first?

A: Short-lived tokens should come first when the primary problem is replay and token theft. Continuous refresh then preserves usability by revalidating the session in the background so users are not forced back through interactive login too often. Together, they reduce attacker dwell time without turning every session into a hard reset.

Technical breakdown

Why token presentation is not proof of trust

A token proves that it was issued and that its signature can be validated, but it does not prove that the current presenter is still the intended actor. If a token is stolen through XSS, man-in-the-middle interception, or a compromised endpoint, the token may remain structurally valid while the trust relationship is broken. Zero Trust token handling closes that gap by re-evaluating the session at the moment of use rather than at issuance.

Practical implication: treat token validation as necessary but insufficient, and evaluate the context around every presentation.

Context binding for device, network, and behaviour

Context binding ties a token to characteristics such as device posture, source network, and behavioural signals so that replay from a different environment becomes detectable. This does not make token theft impossible, but it makes reuse harder to convert into access. It also changes the identity model from static possession to conditional legitimacy, which is closer to how modern Zero Trust decisions should work.

Practical implication: enforce context-aware controls on high-value sessions and deny or step up when the context changes.

Short-lived tokens and continuous refresh

Short-lived tokens reduce the value of theft, while continuous refresh keeps legitimate sessions alive without forcing the user to re-authenticate constantly. The architectural point is that the session becomes ephemeral and continuously re-evaluated, rather than granted once and trusted until expiry. That matters when attackers are able to replay credentials quickly or move between devices within minutes.

Practical implication: shorten token lifetimes where risk is high and pair them with background re-authentication or revalidation.

Threat narrative

Attacker objective: The attacker wants to reuse a valid token to obtain authorised access without needing the original credentials or interactive authentication.

1. Entry occurs when attackers steal or intercept a token through XSS, MITM, or a compromised device, then present it in place of the legitimate actor.
2. Escalation happens when the replayed token is accepted without fresh context checks, allowing the attacker to inherit the original session's privileges.
3. Impact follows when the attacker uses that trusted session to access data or systems while appearing to be the authorised user.

Breaches seen in the wild

• Salesloft OAuth token breach — hackers stole OAuth tokens to access Salesforce data via Salesloft.
• Internet Archive breach — unsecured GitLab authentication tokens exposed 31M Internet Archive accounts.

Read our 52 NHI Breaches Analysis report for a comprehensive view of breaches impacting Non-Human Identities including AI Agents.

NHI Mgmt Group analysis

Token validity is not the same as session legitimacy: The article exposes a control assumption that many identity programmes still carry forward from earlier authentication models. A token can be structurally valid while the surrounding context has changed enough that access should no longer be trusted. The implication is that token governance must be treated as continuous decisioning, not a one-time issuance event.

Zero Trust token handling is really context governance for NHI and human sessions: Device, network, and behavioural context are now part of the authorisation problem, not just the fraud-detection problem. That matters because the same replay risk applies to human tokens, API tokens, and other non-human identities where possession alone is not enough to prove legitimacy. Practitioners should align token policy with the actor type rather than assume a single session model fits all.

Short-lived credentials reduce attacker dwell time but do not solve trust by themselves: The article correctly points to continuous refresh, but the deeper point is that lifecycle compression only helps when paired with state-aware verification. If the token can still be replayed within its lifetime, the governance gap remains. Identity teams should think in terms of reducing the usable window of stolen access, not simply improving expiration hygiene.

Continuous verification is becoming the practical boundary between IAM and fraud control: Once tokens can be stolen from devices, browsers, or middleware, the access decision inherits an abuse-detection problem. That blurs the line between classic IAM and risk-based authentication, especially for high-value workflows where a stolen session can become a low-friction fraud path. Security teams should expect these controls to converge around contextual enforcement and behavioural signals.

Named concept: token trust drift: This article describes the gap between the token's original trust state and the moment it is actually used. Token trust drift grows when replay, device change, or network change is not re-evaluated at presentation time. Practitioners should treat that drift as a first-class identity risk, not an edge-case exception.

From our research:

• 64% of valid secrets leaked in 2022 are still valid and exploitable today, according to The State of Secrets Sprawl 2026.
• The same research found that 28.65 million new hardcoded secrets were detected in public GitHub commits in 2025 alone, a 34% year-over-year increase.
• That combination of exposure volume and residual validity is why the Guide to the Secret Sprawl Challenge matters for teams trying to reduce replayable access windows.

What this signals

Token trust drift: identity programmes need to start treating session context as mutable state, not a one-time trust decision. If the token is still valid but the device, network, or behavioural profile has changed, the access decision is already behind the risk.

The operational implication is that IAM, PAM, and fraud controls are converging around the same question: does the actor still deserve access right now? Teams that can feed context into policy enforcement will reduce replay risk faster than teams that rely on longer expirations or cleaner issuance flows.

With 24,008 unique secrets exposed in MCP configuration files in 2025 alone, the broader lesson is clear: access artefacts spread faster than traditional governance cycles can react, so token and secret lifecycles must be shortened and monitored together.

For practitioners

• Bind tokens to current context Require device, network, and behavioural context checks at presentation time so a replay from a different environment triggers step-up or denial. Focus the strongest checks on privileged or data-rich sessions where token theft has the highest impact.
• Shorten token lifetime where risk is high Use short-lived tokens for sensitive workflows and pair them with continuous refresh so legitimate users keep working while stolen tokens lose value quickly. Apply the shortest TTLs to externally exposed applications and privileged admin paths.
• Detect replay as an identity event Instrument SIEM and identity telemetry to flag repeated token use from mismatched context, abnormal session transitions, or multiple geographies within one validity window. A token that changes context without a corresponding re-authentication event should be treated as suspicious.
• Review token policy by actor type Separate human, workload, and service-token rules so one policy does not overfit to browser sessions or under-protect machine-to-machine access. The correct lifetime, binding strength, and refresh model differ across actor types.

Key takeaways

• Token replay is an authorisation problem, not just a cryptography problem.
• Context binding and short-lived sessions reduce the value of stolen tokens more effectively than signature checks alone.
• Identity teams should treat token trust drift as a governance issue that spans IAM, fraud detection, and NHI access control.

Key terms

• Claim Trust Drift: Claim trust drift is the gap between where a token was issued and where it is later accepted without enough restriction. It happens when audience, issuer, or lifetime controls are too broad, allowing a valid cryptographic token to create invalid access across systems.
• Context binding: Context binding is the practice of attaching business, workflow, and identity-state information to a security event before it is scored or investigated. It turns isolated identity telemetry into interpretable evidence and is essential for distinguishing routine administration from abuse.
• Continuous Verification: A Zero Trust practice that re-evaluates trust during the session instead of relying on a single successful login. The control is stronger when context signals are available in real time and when the identity programme can act on those signals without creating excessive exceptions.

What's in the full article

SecureAuth's full article covers the operational detail this post intentionally leaves for the source:

• Specific examples of how token theft occurs through XSS, MITM, and compromised devices
• The platform's detailed approach to continuous risk scoring and behavioural verification
• How context binding changes session decisions for different identity scenarios
• Deployment considerations for teams using Continuous Authority in production environments

👉 SecureAuth's full article covers token binding, continuous refresh, and the trust assumptions behind session reuse

Deepen your knowledge

NHI governance, agentic AI identity, and machine identity security are core topics in our NHI Foundation Level course, the industry's only accredited NHI security programme. If you are building or maturing an IAM programme, it is worth exploring.