CVE-2026-6911: AWS Ops Wheel Auth Bypass Vulnerability

CVE-2026-6911 Overview

CVE-2026-6911 is a critical authentication bypass vulnerability in AWS Ops Wheel caused by missing JWT signature verification. This flaw allows unauthenticated attackers to forge JWT tokens and gain unintended administrative access to the application, including the ability to read, modify, and delete all application data across tenants and manage Cognito user accounts within the deployment's User Pool, via a crafted JWT sent to the API Gateway endpoint.

Critical Impact

Unauthenticated attackers can forge JWT tokens to gain full administrative control over the application, enabling cross-tenant data manipulation and Cognito user account management without any authentication.

Affected Products

• AWS Ops Wheel (versions prior to the security patch)
• Deployments using AWS API Gateway with the vulnerable JWT validation logic
• Forked or derivative implementations of AWS Ops Wheel

Discovery Timeline

• 2026-04-24 - CVE-2026-6911 published to NVD
• 2026-04-24 - Last updated in NVD database

Technical Details for CVE-2026-6911

Vulnerability Analysis

This vulnerability stems from a critical flaw in the authentication mechanism where JWT signature verification is completely absent. When JWT tokens are processed by the application, the signature component that cryptographically validates the token's authenticity is not being checked. This means an attacker can craft arbitrary JWT payloads with any claims—including administrative privileges—and the application will accept them as valid.

The weakness is classified under CWE-347 (Improper Verification of Cryptographic Signature), indicating that while the application expects signed tokens, it fails to actually verify those signatures before trusting the token contents. This creates a complete authentication bypass scenario where attackers can impersonate any user, including administrators, without possessing valid credentials.

Root Cause

The root cause is the absence of cryptographic signature validation in the JWT processing logic. JWT tokens consist of three parts: a header, payload, and signature. The signature is generated using a secret key and validates that the token hasn't been tampered with. When this verification step is skipped, any token—regardless of whether it was legitimately issued—will be accepted. This allows attackers to create tokens with elevated privileges by simply modifying the payload claims without needing access to the signing key.

Attack Vector

The attack is conducted remotely over the network against the API Gateway endpoint. An attacker crafts a malicious JWT token with administrative claims (such as elevated role assignments or specific user identifiers) and sends it in requests to the API. Since the application does not verify the token's signature, it trusts the forged claims and grants the attacker full administrative access. This enables the attacker to perform cross-tenant data operations and manage Cognito user accounts within the deployment's User Pool.

The attack requires no authentication, no user interaction, and has low complexity—making it highly exploitable. Once successful, attackers can read, modify, and delete all application data across multiple tenants, effectively compromising the entire deployment.

Detection Methods for CVE-2026-6911

Indicators of Compromise

• Unusual JWT tokens with unexpected or elevated privilege claims appearing in API Gateway logs
• Authentication events from IP addresses or user agents not typically associated with legitimate administrative users
• Cross-tenant data access patterns that deviate from normal operational behavior
• Cognito user account modifications (creation, deletion, permission changes) without corresponding legitimate administrator sessions

Detection Strategies

• Implement logging and alerting on all administrative operations, particularly those involving Cognito user management
• Monitor API Gateway access logs for requests containing JWT tokens with suspicious claim patterns
• Deploy Web Application Firewall (WAF) rules to detect and block malformed or suspicious JWT token structures
• Correlate authentication events with known user behavior baselines to identify anomalous access patterns

Monitoring Recommendations

• Enable detailed CloudWatch logging for API Gateway endpoints to capture all incoming requests and JWT token metadata
• Set up alerts for administrative actions performed outside of expected business hours or from unexpected geographic locations
• Implement real-time monitoring of Cognito User Pool events for unauthorized account modifications
• Review access patterns regularly to identify potential exploitation attempts or post-compromise activity

How to Mitigate CVE-2026-6911

Immediate Actions Required

• Redeploy AWS Ops Wheel from the updated repository containing the security fix
• Audit all forked or derivative codebases to ensure the JWT signature verification patch has been incorporated
• Review API Gateway and Cognito logs for any signs of exploitation prior to patching
• Rotate any secrets or credentials that may have been exposed through administrative access

Patch Information

To remediate this issue, users should redeploy from the updated repository and ensure any forked or derivative code is patched to incorporate the new fixes. The security patch is available through GitHub Pull Request #164. Additional details can be found in the AWS Security Bulletin 2026-018 and the GitHub Security Advisory GHSA-v5vr-8w3c-37x2.

Workarounds

• Restrict network access to the API Gateway endpoint using security groups or VPC configurations until patching is complete
• Implement additional authentication layers such as IP allowlisting or client certificate validation as temporary controls
• Deploy a Web Application Firewall (WAF) with custom rules to inspect and validate JWT token structures before they reach the application
• Consider temporarily disabling public access to the affected deployment if business operations permit

The vulnerability mechanism involves the application accepting JWT tokens without validating their cryptographic signatures. In a properly secured implementation, the server would verify that the signature portion of the JWT was generated using the expected secret or public key. Without this verification, any attacker can create a token with arbitrary claims and have it accepted. For detailed technical information about the fix, refer to the GitHub Security Advisory.