Your developers understand the difference between access tokens and refresh tokens. They know access tokens expire quickly and refresh tokens enable persistent sessions. What they may not realize: from a security perspective, these tokens represent fundamentally different threat models. An access token stolen today is a 30-minute problem. A refresh token stolen today is a problem for the next six months.
Most security teams focus on preventing credential theft at the login boundary. SSO and MFA protect the front door. But once OAuth tokens are issued, they operate independently of your authentication controls. Both access tokens and refresh tokens bypass MFA after initial authentication. The critical difference lies in their lifetimes, which create vastly different windows of opportunity for attackers.
Key Takeaways
- Access tokens grant short-lived access to resources (15-60 minutes), while refresh tokens enable long-term session persistence (days to months)
- Both token types are bearer tokens that bypass MFA after issuance, but refresh tokens present significantly higher risk due to extended validity periods
- Refresh token theft is harder to detect because attackers can pace activity over weeks to blend with normal usage patterns, unlike the compressed activity window of access token abuse
- Refresh token rotation is now critical security practice, invalidating entire token families upon detecting reuse to prevent indefinite access from compromised tokens
- Traditional security tools provide token inventory but lack behavioral detection capabilities needed to identify when legitimate tokens are being abused by attackers
One Expires in Minutes. One Lasts for Months. Both Bypass Your MFA.
The OAuth 2.0 framework relies on two distinct token types to balance security and user experience. Access tokens provide the working credential for data access. Refresh tokens enable persistent sessions without repeated authentication. Both are bearer tokens, meaning whoever possesses them can use them. Neither requires MFA validation after initial issuance.
This creates a fundamental security challenge: your authentication controls protect the initial login, but they provide zero protection against token theft. An attacker who obtains either token type can access your SaaS data without ever touching your identity provider. The question becomes: how long can they maintain that access?
For access tokens, the answer is measured in minutes. For refresh tokens, the answer is measured in months. This difference transforms how security teams must approach token theft detection and response.
Access Tokens: The Short-Lived Resource Key
What They Do
Access tokens serve as temporary authorization credentials that grant specific permissions to protected resources. When your application needs to read a user's email, write to their Salesforce instance, or access their Google Drive, it presents an access token to prove authorization. The resource server validates the token and grants access based on the encoded scopes and permissions.
These tokens are the working credential in every API request. They're sent with each call to prove the client has permission to perform the requested action. From a security perspective, access tokens represent the immediate threat surface because they directly enable data access.
How Long They Last
Access token lifetimes are deliberately short to limit exposure from theft. Typical configurations range from 15 to 60 minutes, with many organizations setting even shorter windows. Microsoft's identity platform assigns random lifetimes between 60-90 minutes by default, while other providers may use different ranges based on client type and risk profile.
This short lifetime creates a natural containment mechanism. If an access token is stolen, the attacker has a limited window to exploit it before the token expires and becomes useless. The application must possess a valid refresh token to obtain a new access token and continue operating.
Security Characteristics
Access tokens are bearer tokens, meaning they function like physical keys. Whoever possesses the token can use it, with no validation of the sender's identity by default. This makes them vulnerable to:
- Interception in network traffic if not properly encrypted
- Exposure in application logs that capture request headers
- Theft from browser storage in single-page applications
- Leakage through Referer headers when navigating to external sites
However, the limited validity window constrains the damage from theft. An attacker who steals an access token must act quickly. They have minutes, not days, to exfiltrate data before the token expires. This compressed timeline often creates detectable activity patterns that security teams can identify and respond to before significant damage occurs.
Refresh Tokens: The Persistent Access Mechanism
What They Do
Refresh tokens serve a single purpose: obtaining new access tokens without requiring user interaction. They enable the "stay logged in" functionality users expect from modern applications. They keep integrations running continuously without prompting for re-authentication. They're the mechanism that allows your Salesforce-to-Slack integration to function 24/7 without manual intervention.
Unlike access tokens, refresh tokens are never sent to resource servers. They're only transmitted to the authorization server during token refresh operations. This limited exposure reduces certain attack vectors but doesn't eliminate the fundamental risk: refresh tokens provide persistent access that operates completely outside MFA controls.
How Long They Last
Refresh token lifetimes vary dramatically based on client type and security configuration. Microsoft's identity platform sets 24-hour limits for single-page applications but allows 90-day validity for other scenarios. Okta defaults to unlimited lifetime with automatic expiration after 7 days of non-use, though actual lifetime depends on rotation settings and access policy configuration.
Some organizations configure refresh tokens with no expiration at all, enabling truly persistent sessions that last until explicitly revoked. This creates scenarios where a refresh token stolen today could provide access for months or even years if rotation and monitoring aren't properly implemented.
Security Characteristics
Refresh tokens share the bearer token vulnerability of access tokens but with far more severe implications. Because they're only sent to the authorization server, they're less exposed to certain interception vectors. However, when compromised, they grant attackers something far more valuable than brief access: time.
An attacker with a stolen refresh token can:
- Obtain fresh access tokens on demand for months after initial compromise
- Pace data exfiltration to avoid detection through volume-based alerts
- Establish additional persistence mechanisms while maintaining legitimate-looking access
- Explore the environment slowly to identify high-value targets before extraction
The Salesloft-Drift incident demonstrated this threat model in practice. Compromised refresh tokens enabled sustained access to 700+ organizations, with attackers riding trusted OAuth connections across multiple SaaS applications. The tokens functioned exactly as designed, making the malicious activity nearly indistinguishable from legitimate automation.
Access Token vs Refresh Token: Key Differences Explained Through Security Impact
The technical differences between access tokens and refresh tokens translate directly into divergent threat models that security teams must understand and address.
Dimension Access Token Refresh Token Lifetime 15-60 minutes Days to months If stolen Brief exposure window Persistent access Sent to Resource servers (your data) Authorization server only MFA applied Only at initial auth Never after issuance Detection difficulty Easier (short window) Harder (looks like normal usage) Revocation urgency Less critical Critical
Access Tokens: The Immediate Threat
When an attacker obtains an access token, they gain immediate capability to read or write data based on the token's scopes. The clock starts ticking immediately. They must exfiltrate data, establish persistence, or achieve their objective within the token's validity window.
This urgency often creates detectable patterns. Attackers who steal access tokens typically exhibit:
- Compressed activity timelines with unusual volume
- Geographic anomalies if accessing from unexpected locations
- Behavioral deviations from the legitimate user's baseline patterns
If your security team detects the compromise within the access token's lifetime, you can respond before the attacker obtains a new token. The short window limits damage potential, though the impact can still be significant depending on the token's scopes and the attacker's efficiency.
Refresh Tokens: The Persistent Threat
Refresh token theft represents a fundamentally different threat profile. The attacker isn't racing against a 30-minute countdown. They have days, weeks, or months to execute their objectives. This extended timeline enables sophisticated attack patterns that are far harder to detect.
An attacker with a stolen refresh token can:
- Establish behavioral baselines by observing normal usage patterns before acting
- Blend exfiltration into routine access patterns to avoid volume-based detection
- Rotate through different access patterns to evade anomaly detection
- Maintain access even as the organization rotates access tokens or updates configurations
The behavioral detection challenge is significant. When refresh token usage occurs over weeks, individual access events look identical to legitimate automation. Without understanding the full context of token behavior over time, security teams cannot distinguish compromised tokens from authorized integrations.
The Detection Challenge: Why Token Type Matters for Security Operations
Why Access Token Theft Is Easier to Detect
Access token compromise typically produces concentrated activity within a compressed timeframe. An attacker who steals a 30-minute access token must act immediately, creating behavioral anomalies that stand out against baseline patterns.
Security teams can detect access token abuse through:
- Unusual data access patterns inconsistent with user role or history
- Geographic or network anomalies indicating access from unexpected ASNs
- Volume spikes within the access window that exceed normal usage
- Temporal anomalies such as access during unusual hours for that user
The short validity window works in defenders' favor. If you detect suspicious activity and respond within the token lifetime, you can prevent the attacker from obtaining a new token and continuing their access.
Why Refresh Token Theft Is Harder to Detect
Refresh token compromise enables patient, methodical attacks that evade traditional detection mechanisms. Because attackers can pace their activity over weeks or months, they can carefully blend into normal usage patterns.
Consider the detection challenges:
- Long timeline means activity spreads across many days, diluting anomaly signals
- Slow exfiltration avoids volume-based alerts designed to catch bulk downloads
- Behavioral adaptation allows attackers to observe and mimic normal patterns
- Legitimate appearance since refresh tokens are designed for automated, ongoing access
Traditional security tools that focus on point-in-time analysis or volume thresholds will miss these attacks entirely. The activity looks identical to authorized integrations performing their intended functions. Without behavioral baselines and anomaly detection specifically designed for OAuth token usage, compromised refresh tokens remain invisible.
What Security Teams Need to Monitor for Token Abuse Detection
For Access Tokens
Effective access token monitoring requires real-time behavioral analysis focused on the compressed activity window. Security teams should track:
- Unusual data access patterns such as accessing resources the user rarely touches
- Geographic or network anomalies including new ASNs or residential proxy indicators
- Volume spikes that exceed the user's historical baseline within the token lifetime
- Scope escalation where token usage attempts actions beyond granted permissions
These signals become meaningful when correlated with user behavior baselines and analyzed within the context of the access token's short validity period. A 30-minute window of unusual activity is far more suspicious than the same activity spread over three days.
For Refresh Tokens
Refresh token monitoring demands a fundamentally different approach focused on long-term behavioral patterns and token lifecycle anomalies. Critical monitoring areas include:
- Token rotation failures indicating reuse detection has triggered
- Changes in usage patterns over time such as new resource access or scope expansion
- New source networks or ASNs appearing in refresh token usage after establishment
- Refresh frequency anomalies deviating from the application's normal token refresh cadence
Organizations implementing refresh token rotation gain additional detection capabilities. When rotation is enabled, the authorization server issues both a new access token and a new refresh token with each refresh request. If the old refresh token is used again, it indicates either a compromised token or a client implementation error. The server can invalidate the entire token family, forcing re-authentication and breaking the attacker's access.
The Real Question: Do You Have Visibility Into Either?
Most organizations log OAuth consent events when users authorize applications. Fewer log token issuance. Almost none monitor token usage behavior in a way that enables detection of compromise.
This visibility gap creates a fundamental security blind spot. Your security team may know that 1,247 OAuth tokens exist across your SaaS environment. But can you answer:
- Which tokens have access to your most sensitive data?
- What baseline behavior patterns do those tokens exhibit?
- When did token usage patterns change in ways that indicate compromise?
- Which tokens represent toxic combinations of overprivileged permissions?
What Visibility Requires
Effective token security requires capabilities beyond traditional security tools:
Discovery of all tokens across SaaS environment including both first-party and third-party integrations that create hidden OAuth connections one integration away from your managed applications.
Mapping of what data each token can access based on granted scopes, inherited permissions, and the actual resources the token touches during normal operation.
Behavioral baseline for normal usage established through continuous monitoring of token activity patterns, refresh frequency, source networks, and data access profiles.
Anomaly detection when patterns change identifying deviations that indicate token compromise, such as new ASNs, unusual refresh timing, or access to previously untouched resources.
The Inventory vs. Detection Gap
Token inventory tells you tokens exist. Token behavior detection tells you tokens are being abused. Without behavioral detection, compromised tokens look identical to legitimate ones.
Traditional security tools provide static visibility: a snapshot of what tokens exist at a point in time. This inventory approach misses the dynamic reality of SaaS-to-SaaS lateral movement where attackers use stolen tokens to ride trusted connections across your application ecosystem.
The gap between inventory and detection creates the blind spots where attackers operate. Your CASB may show you that an OAuth integration exists. Your SSPM may flag overprivileged scopes. But neither tells you when that integration's refresh token was stolen three weeks ago and is now being used to slowly exfiltrate customer data from a residential proxy network.
Refresh Token Rotation: Critical Security Practice for 2026
RFC 9700 (Best Current Practice for OAuth 2.0 Security, published January 2025) establishes refresh token rotation as essential security practice, updating threat models from earlier OAuth specifications to address practical attack patterns observed in production environments.
How Token Rotation Works
When refresh token rotation is enabled, each token refresh operation returns both a new access token and a new refresh token. The previous refresh token is immediately invalidated. This creates a chain of single-use refresh tokens rather than a single persistent token that remains valid indefinitely.
If an attacker attempts to reuse a previously-used refresh token, the authorization server detects the anomaly and can invalidate the entire token family, forcing both the legitimate user and the attacker to re-authenticate. This breaks the attacker's persistent access and creates a detection event.
Grace Periods and Implementation Considerations
To prevent legitimate clients from losing access due to network timing issues, authorization servers typically implement grace periods. Okta defaults to 30 seconds, allowing the previous refresh token to remain valid briefly after rotation. This prevents race conditions where a client requests a new token but doesn't receive the response before the old token expires.
Organizations implementing rotation must balance security and reliability. Shorter grace periods reduce the window for token reuse attacks but increase the risk of legitimate clients losing access due to network delays.
Rotation for Public Clients
Public clients such as single-page applications present the highest risk for refresh token compromise because they cannot securely store credentials. For these clients, refresh token rotation should be mandatory, and token lifetimes should be minimized.
Microsoft limits SPA refresh tokens to 24 hours regardless of rotation settings. Combined with rotation, this creates a maximum exposure window of one day for any stolen token, significantly reducing the persistent threat compared to 90-day or unlimited refresh tokens.
Understanding Your Token Exposure: The Path Forward
Both access tokens and refresh tokens are accessing your data right now. The question isn't whether you use OAuth tokens-every modern SaaS environment does. The question is whether you understand which tokens exist, what they can access, and when their behavior indicates compromise.
Traditional security approaches focus on preventing token theft through authentication controls. But as this analysis demonstrates, both access tokens and refresh tokens bypass MFA after initial issuance. Prevention alone cannot address the threat model. Detection becomes critical.
Security teams need capabilities that go beyond static inventory to provide behavioral detection:
- Discover all OAuth tokens across your SaaS environment, including third-party integrations that create hidden connections
- Categorize tokens by risk level based on scopes, permissions, and access to sensitive data
- Establish behavioral baselines for normal token usage patterns
- Detect anomalies that indicate token compromise, such as new source networks, unusual refresh patterns, or changes in data access profiles
Organizations experiencing integration blind spots, failed audits, or vendor breach notifications need visibility into the hidden layer where OAuth tokens operate. Without this visibility, security teams cannot answer basic questions about their token exposure, let alone detect when tokens are being abused by attackers.
Conclusion
Access Token vs Refresh Token: Key Differences Explained reveals that these two token types represent fundamentally different threat models. Access tokens provide brief windows of access measured in minutes. Refresh tokens enable persistent access measured in months. Both bypass MFA. Both are bearer tokens. But their lifetimes create vastly different challenges for security teams.
The security industry has spent years focusing on preventing credential theft at the authentication boundary. SSO and MFA protect the login. But they provide zero protection against token theft. Once OAuth tokens are issued, they operate independently of your identity controls.
Understanding the difference between access tokens and refresh tokens isn't just a developer concern. It's a security imperative. Access token theft is a sprint. Refresh token theft is a marathon. Your detection capabilities must address both threat models.
Organizations that rely on static token inventory without behavioral detection will continue to miss compromised tokens operating in plain sight. The tokens look legitimate because they are legitimate-they're just being used by the wrong party. Only behavioral analysis can distinguish authorized usage from abuse.
Obsidian Security discovers all OAuth tokens across your SaaS environment, categorizes them by risk level based on scopes and data access, and detects behavioral anomalies that indicate compromise. Our Knowledge Graph approach correlates token usage with user behavior, ASN deviation, User-Agent attribution, and access patterns to identify when legitimate tokens are being abused.
See which tokens present the greatest risk to your organization. Request a demo to understand your OAuth token exposure and gain the behavioral detection capabilities needed to identify token compromise before attackers complete their objectives.
