CVE-2026-108731 in Raven
Summary
by MITRE • 10/11/2026
Raven 2.0.0 through 3.0.0 contains a missing authorization vulnerability that allows authenticated users to join invite-only Public workspaces by ignoring the can_only_join_via_invite setting. Attackers with the Raven User role can call the join_workspace method to become persistent members, reading and posting in Public and Open channels.
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Analysis
by VulDB Data Team • 10/11/2026
The identified security flaw resides within Raven versions 2.0.0 through 3.0.0 and represents a critical failure in access control mechanisms, specifically categorized under CWE-862 Missing Authorization. This vulnerability allows authenticated users to bypass intended restrictions on workspace membership by exploiting the join_workspace method without proper validation of their eligibility. The core technical issue stems from the application's failure to enforce the can_only_join_via_invite setting when processing requests to enter invite-only Public workspaces. Consequently, any user possessing the Raven User role can circumvent administrative controls designed to restrict entry to specific individuals or groups who have been explicitly invited by workspace administrators.
From an operational perspective, this lack of authorization enforcement enables unauthorized users to become persistent members of sensitive environments. Once inside these invite-only Public workspaces, attackers gain the ability to read messages and post content in both Public and Open channels that were intended to be restricted. This breach compromises the confidentiality and integrity of communications within those spaces, potentially exposing proprietary information, internal discussions, or other confidential data to individuals who should not have access. The persistence of this membership means that even if an administrator attempts to remove the user later, the attacker may retain historical access logs or cached data depending on how the application handles session termination and data retention policies.
The attack vector is relatively straightforward for any authenticated actor with basic API interaction capabilities, as it involves calling a standard method without requiring complex exploitation techniques such as buffer overflows or injection attacks. This simplicity increases the likelihood of successful exploitation in environments where authentication credentials may be compromised through phishing, credential stuffing, or other common compromise scenarios. The vulnerability aligns with ATT&CK technique T1078 Valid Accounts, as it relies on legitimate but improperly authorized user accounts to gain unauthorized access to resources. Furthermore, it reflects CWE-269 Improper Privilege Management due to the elevation of capabilities beyond what is permitted by the workspace configuration settings.
To mitigate this vulnerability, immediate action should be taken to upgrade Raven to a version where this authorization check has been properly implemented and tested. In the interim, administrators can implement compensating controls such as monitoring for unusual join activity patterns or restricting API access based on IP reputation if feasible within their infrastructure constraints. It is also advisable to review workspace settings to ensure that no other invite-only workspaces are exposed to similar risks by auditing all instances of the join_workspace method calls and verifying that authorization checks are consistently applied across all entry points. Regular security audits and penetration testing focusing on access control logic will help identify similar flaws in future updates or related modules within the Raven ecosystem.