CVE-2026-101046 in Fleet
Summary
by MITRE • 09/27/2026
Fleet before 4.89.0 contains an SQL injection vulnerability in the activity list endpoints (GET /api/v1/fleet/activities and GET /api/v1/fleet/hosts/{id}/activities). The deprecated cursor-pagination helper appendListOptionsWithCursorToSQL interpolated the caller-supplied sort/order key into the SQL ORDER BY clause without an allowlist, so an authenticated user with read access to Activity could order results by arbitrary columns. The impact is read-only and bounded to columns on the activity_past table that are not otherwise returned in these responses (e.g. details), allowing their values to be inferred through the resulting sort order; there is no write access, privilege escalation, or reachability of node_key or other host-join columns through these endpoints. Fixed in 4.89.0, which removes the deprecated helper and passes the sort column through SanitizeColumn.
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Analysis
by VulDB Data Team • 09/27/2026
The vulnerability identified in Fleet versions prior to 4.89.0 represents a classic SQL injection flaw rooted in improper validation of user-supplied input within database query construction logic. Specifically, the defect resides in two API endpoints designed for retrieving activity logs: GET /api/v1/fleet/activities and GET /api/v1/fleet/hosts/{id}/activities. These endpoints utilize a deprecated helper function named appendListOptionsWithCursorToSQL to manage pagination and sorting parameters provided by the client. The core technical failure occurs when this helper interpolates caller-supplied sort or order keys directly into the SQL ORDER BY clause of the generated query without applying an allowlist mechanism for validation. In secure software development, any user input that influences database structure must be strictly validated against a predefined set of acceptable values to prevent injection attacks. By failing to enforce such constraints, the application inadvertently allows authenticated users with read access to activity data to manipulate the underlying SQL statement's sorting logic.
From an operational perspective, this vulnerability is classified as read-only and does not grant write privileges or allow for privilege escalation. The attacker cannot execute arbitrary commands on the database server nor modify existing records through these specific endpoints. However, the ability to order results by arbitrary columns introduces a significant information disclosure risk. Because the sort order can be manipulated based on values in columns that are otherwise hidden from the response payload, an attacker can perform inference attacks. For instance, if a column such as details is not returned directly but its value influences the sorting outcome, an attacker could potentially deduce sensitive data by observing how results are ordered under different conditions. This technique leverages blind SQL injection principles where the application's behavior serves as a side channel for extracting information about database contents that should remain confidential.
The security impact is further contextualized within industry standards such as CWE and MITRE ATT&CK. The vulnerability aligns with CWE-89, which describes Improper Neutralization of Special Elements used in an SQL Command, commonly known as SQL Injection. More specifically, it reflects a failure to validate input against expected values before use in dynamic query construction. In the context of the MITRE ATT&ACK framework, this behavior facilitates Data from Information Repositories under the T1074 data staging or exfiltration techniques if combined with other vectors, but primarily here it represents an unauthorized access and information gathering capability (T1538). The lack of input validation on sort parameters is a common oversight in web applications that prioritize developer convenience over security hardening, particularly when using legacy helper functions that may not adhere to modern secure coding practices.
Mitigation for this vulnerability was implemented in Fleet version 4.89.0 through the removal of the deprecated appendListOptionsWithCursorToSQL helper function entirely. This architectural change eliminates the code path responsible for the unsafe interpolation. Furthermore, the updated implementation ensures that sort column parameters are passed through a SanitizeColumn routine before being used in SQL queries. This sanitization process acts as an allowlist mechanism, ensuring that only predefined, safe column names can be utilized for sorting operations. Organizations running Fleet versions earlier than 4.89.0 must upgrade immediately to close this information disclosure vector. Additionally, while the direct exploitability is limited by authentication requirements and read-only access, it remains critical to audit API endpoints for similar patterns of dynamic SQL construction in other parts of the application ecosystem to prevent analogous vulnerabilities from being introduced elsewhere.