CVE-2026-88029 in Python Driver
Summary
by MITRE • 09/10/2026
Improper neutralization of special elements in data query logic in the GridFS component of the MongoDB Python Driver can cause a caller-supplied structured file identifier to be interpreted as a query condition rather than as a literal identifier. An authenticated user who can influence the identifier passed by an affected application may obtain stored file content beyond the intended target or cause all GridFS file chunks in the affected bucket to be removed, rendering stored file content unreadable. The affected rename operation may also rename a stored file other than the intended target.
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Analysis
by VulDB Data Team • 09/10/2026
The vulnerability identified as Improper Neutralization of Special Elements in Data Query Logic within the MongoDB Python Driver’s GridFS component represents a critical injection flaw that compromises data integrity and confidentiality. This issue stems from how the driver processes structured file identifiers during operations such as rename or delete. In normal operation, these identifiers are intended to be treated as literal values used for exact matching against stored records. However, due to improper sanitization of input parameters, an attacker who can influence the identifier passed by a vulnerable application may cause the database engine to interpret parts of that identifier as query conditions rather than static data. This misinterpretation allows structured elements within the file ID to alter the logic of the underlying database queries, effectively turning what should be a simple lookup into a complex filter operation with unintended side effects.
From an operational perspective, this flaw has severe consequences for applications relying on GridFS for large file storage and management. An authenticated user or attacker who controls the input passed to affected functions can exploit this logic error to bypass intended access controls. Specifically, by crafting a maliciously structured file identifier, the attacker can manipulate the query criteria used during rename operations. This capability allows them to target files other than the one originally intended for modification. Consequently, sensitive data may be inadvertently moved or overwritten, leading to significant operational disruptions and potential loss of critical business assets. The ability to misdirect administrative actions undermines the reliability of file management systems built on top of MongoDB GridFS.
Furthermore, the impact extends beyond mere misdirection of rename operations. In more severe scenarios, particularly involving delete functions, an attacker can exploit this vulnerability to remove all chunks associated with a specific bucket rather than just those belonging to a single target file. This results in the complete deletion of stored content within that bucket, rendering all files stored there unreadable and effectively causing a denial of service for any application dependent on that data store. Additionally, by manipulating query logic, an attacker might be able to broaden search criteria to retrieve file contents beyond their intended authorization scope. This constitutes a serious breach of confidentiality, as it allows unauthorized access to sensitive documents stored in the GridFS system without requiring additional authentication or privilege escalation steps beyond what is already granted for basic file operations.
This vulnerability aligns with CWE-78 Improper Neutralization of Special Elements used in an OS Command or similar injection flaws where input data influences command structure, although here it specifically affects database query construction logic rather than shell commands. It also maps to ATT&CK technique T1059 Command and Scripting Interpreter if viewed through the lens of manipulating backend processes, but more accurately reflects CWE-89 SQL Injection principles adapted for NoSQL environments where object structures are parsed into query filters. The core issue is a failure to ensure that user-supplied data remains strictly within its expected semantic context as a literal value rather than executable logic.
To mitigate this risk, developers must upgrade the MongoDB Python Driver to versions that include patches addressing this input validation flaw. It is crucial to verify that all calls to GridFS functions such as rename and delete pass only simple, non-structured identifiers unless explicitly intended for complex querying with proper sanitization. Applications should implement strict type checking on file IDs before passing them to driver methods, ensuring they conform to expected formats like ObjectId strings without embedded operators or special characters that could be misinterpreted by the database engine. Additionally, applying the principle of least privilege ensures that even if an attacker exploits this flaw, their ability to perform destructive actions like bulk deletion is restricted by role-based access controls configured within MongoDB itself. Regular security audits and static code analysis tools should be employed to detect similar patterns where user input directly influences query construction logic in other parts of the application stack.