CVE-2026-100540 in Feishu
Summary
by MITRE • 09/26/2026
OpenClaw Feishu before 2026.8.1 fails to validate whether a configured default account is disabled before selecting it for model tool operations. Attackers can exploit multi-account setups where a disabled default account retains credentials to read or modify Feishu resources through a revoked identity.
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Analysis
by VulDB Data Team • 09/26/2026
The vulnerability identified in OpenClaw Feishu prior to version 2026.8.1 represents a critical authentication logic flaw that undermines the integrity of access control mechanisms within multi-account configurations. The core technical deficiency lies in the application's failure to perform adequate state validation on user accounts before initiating model tool operations. Specifically, when an administrator or system component configures a default account for automated tasks or API interactions, OpenClaw Feishu does not verify whether that specific account has been disabled by the identity provider or administrative policy. This oversight allows the software to proceed with authentication and authorization processes using credentials associated with an inactive user profile, effectively bypassing standard access revocation protocols.
From a technical perspective, this flaw constitutes a classic case of improper privilege management where the system trusts stored credential data without validating the current status of the associated identity entity. In typical enterprise environments, when an account is disabled, its permissions are immediately revoked to prevent unauthorized access. However, because OpenClaw Feishu fails to check the active or inactive state of the default account before selecting it for operations, it continues to utilize the existing session tokens or API keys linked to that identity. This behavior creates a persistent backdoor through which attackers can maintain access even after an administrator has attempted to revoke privileges by disabling the user account.
The operational impact of this vulnerability is severe in environments where automated tools interact with sensitive Feishu resources such as documents, spreadsheets, and communication channels. An attacker who gains control over the OpenClaw configuration or exploits a related injection vector can leverage these disabled credentials to read confidential information or modify critical data within the Feishu ecosystem. This capability allows for unauthorized data exfiltration, tampering with business-critical records, and potential lateral movement if those resources contain further sensitive intelligence. The risk is particularly acute in organizations that rely on automated workflows driven by service accounts or default user profiles, as these are often granted elevated permissions to facilitate seamless operation across the platform.
This vulnerability aligns closely with CWE-284 Improper Access Control, specifically regarding the failure to enforce proper authorization checks during resource access. Furthermore, it maps to MITRE ATT&CK technique T1078 Valid Accounts, where adversaries use legitimate credentials that have not been properly revoked due to administrative oversight or software logic errors. The exploitation of this flaw enables attackers to operate under a guise of legitimacy, making detection through standard anomaly monitoring more difficult since the activity appears to originate from an authorized identity, albeit one that should no longer be active.
To mitigate this risk, organizations must immediately upgrade OpenClaw Feishu to version 2026.8.1 or later, where the validation logic has been corrected to ensure disabled accounts are rejected during tool operation selection. In addition to patching, administrators should implement a defense-in-depth strategy by regularly auditing configured default accounts and ensuring that any account designated for automated tasks is monitored closely for status changes. It is also advisable to enforce strict separation of duties between administrative identity management and application-level credential storage, ensuring that applications do not retain references to identities that have been explicitly disabled in the central directory service. Regular penetration testing focused on authentication bypass scenarios can further help identify similar logic flaws before they are exploited in production environments.