CVE-2026-56249 in Capgo
Summary
by MITRE • 07/01/2026
Capgo before 12.128.2 contains an authorization bypass vulnerability in the channel creation endpoint that allows authenticated users to overwrite existing channels by reusing their names. Attackers with app.create_channel permission can exploit a logic mismatch between existence validation and upsert operations to reassign channel ownership and modify critical production channel configurations.
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Analysis
by VulDB Data Team • 07/01/2026
This vulnerability exists within the Capgo platform version 12.128.1 and earlier, representing a critical authorization bypass flaw that undermines the system's access control mechanisms. The issue stems from a fundamental logic mismatch in the channel creation endpoint where the validation process for channel existence does not properly synchronize with the subsequent upsert operations. This discrepancy allows authenticated users to exploit a race condition or logical gap in the permission model, enabling them to manipulate channel configurations beyond their intended authorization scope.
The technical exploitation occurs through a specific sequence where an attacker with the app.create_channel permission can attempt to create a channel using a name that already exists within the system. Due to the flawed implementation, the system performs existence checks that may not adequately prevent concurrent or sequential operations from overwriting existing channel configurations. This authorization bypass represents a CWE-284 access control vulnerability where the system fails to properly enforce authorization boundaries during critical operations.
The operational impact of this vulnerability extends beyond simple privilege escalation, as attackers can potentially reassign channel ownership to themselves and modify critical production configurations that govern application behavior and data flow. This capability enables malicious actors to disrupt service availability, manipulate data routing, or gain unauthorized access to sensitive information within the affected channels. The vulnerability particularly threatens production environments where channel configurations control essential application functionality and security parameters.
Security practitioners should implement immediate mitigations including strengthening the validation logic between existence checks and upsert operations, implementing proper race condition handling mechanisms, and enforcing stricter authorization controls during channel creation and modification processes. Additionally, organizations should consider implementing audit logging for all channel creation and modification activities to detect unauthorized configuration changes. This vulnerability aligns with ATT&CK technique T1078 credential reuse and T1496 resource hijacking, as it enables attackers to assume control over existing resources and manipulate their configurations without proper authorization. The remediation approach should include comprehensive code review of all upsert operations, implementation of atomic operations that prevent concurrent modifications, and enhanced permission validation at multiple layers of the system architecture to ensure proper isolation between different user roles and channel configurations.