CVE-2026-76238 in stigmem
Summary
by MITRE • 08/19/2026
stigmem versions before 0.9.0a12 contain a broken object level authorization vulnerability in the decay sweep endpoint that allows authenticated attackers with write credentials for one tenant to execute decay operations affecting all tenants. Attackers can submit POST requests to the decay sweep endpoint with ttl_seconds=0 to expire facts across all tenants, or use dry_run to obtain cross-tenant fact counts and existence information.
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Analysis
by VulDB Data Team • 08/19/2026
The vulnerability identified in stigmem versions prior to 0.9.0a12 represents a critical failure in access control mechanisms, specifically categorized under the Broken Object Level Authorization (BOLA) flaw type within the Common Weakness Enumeration framework as CWE-639. This security defect resides within the decay sweep endpoint of the application architecture, which is designed to manage the expiration and cleanup of factual data based on time-to-live parameters. The core technical issue stems from a lack of proper tenant isolation checks during the execution of these decay operations. When an authenticated user with write credentials for a specific tenant initiates a request against this endpoint, the backend logic fails to validate whether the requested operation is scoped strictly to that single tenant's data partition or if it inadvertently applies globally across all tenants hosted on the same instance.
This architectural oversight allows malicious actors who possess valid authentication tokens and write permissions for any one tenant to exploit the endpoint by manipulating specific parameters in their HTTP POST requests. By setting the ttl_seconds parameter to zero, an attacker can trigger a decay sweep that expires facts belonging not only to their authorized tenant but also to all other tenants sharing the infrastructure. This action results in widespread data loss or unavailability, effectively causing a denial of service condition for legitimate users across multiple organizations. The severity is compounded by the fact that this operation does not require administrative privileges, relying solely on standard write access granted to lower-level application roles, thereby expanding the potential attack surface significantly.
Beyond direct data destruction, the vulnerability also facilitates information disclosure through the use of the dry_run parameter. When an attacker submits a request with dry_run enabled, the system returns metadata regarding fact counts and existence without actually deleting or modifying the underlying data. This behavior allows adversaries to enumerate facts across all tenants, gaining insight into the volume and presence of sensitive records belonging to other organizations. Such reconnaissance capabilities can be leveraged for further attacks, including targeted social engineering or planning more sophisticated exploitation attempts against specific high-value targets within those affected tenants.
From a threat intelligence perspective, this vulnerability aligns with MITRE ATT&CK techniques related to Privilege Escalation and Data Exfiltration, specifically mapping to the concept of abusing application logic flaws to bypass intended restrictions. The ability to perform cross-tenant operations violates fundamental principles of multi-tenancy security, where data isolation is paramount for maintaining confidentiality and integrity in shared software environments. Organizations relying on stigmem must recognize that this flaw undermines trust between tenants sharing the same deployment instance, potentially leading to significant compliance violations depending on regulatory requirements such as GDPR or HIPAA regarding data segregation.
To mitigate this risk, immediate action should be taken by upgrading the stigmem installation to version 0.9.0a12 or later, where these authorization checks have been corrected to enforce strict tenant scoping for all decay sweep operations. In environments where an upgrade is not immediately feasible, network-level controls such as Web Application Firewalls can be configured to restrict access to the affected endpoint based on IP reputation or behavioral anomalies, although this provides only a partial defense in depth. Additionally, implementing rigorous input validation and ensuring that backend services explicitly verify tenant identifiers against user session contexts before executing any data modification queries is essential for preventing similar logic flaws in other parts of the application stack. Regular security audits focusing on object-level authorization patterns are recommended to identify and remediate analogous vulnerabilities across the entire codebase.