CVE-2026-9737 in Server
Summary
by MITRE • 07/22/2026
During query planning when reading the sort pattern in raw BSONObj form, in some places we don’t explicitly handle the meta expression case. This may lead to incorrect transformations leading to invariant failure.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 07/22/2026
This vulnerability occurs during MongoDB's query planning phase when processing sort patterns encoded in raw BSONObj format. The flaw manifests when the system encounters meta expressions within sort operations but fails to explicitly handle these cases during transformation processes. The issue stems from incomplete validation logic that does not account for all possible BSON expression types during query optimization, particularly when dealing with metadata-oriented sorting directives.
The technical implementation problem arises from the query planner's failure to properly recognize and process meta expressions within sort patterns, which are typically used for advanced sorting operations such as text search scoring or other metadata-based ordering. When these expressions are encountered without proper handling, the system attempts transformations that violate internal invariants, leading to crashes or inconsistent database states. This represents a classic control flow vulnerability where improper input validation leads to unexpected program behavior.
The operational impact of this vulnerability extends beyond simple query failures, as it can result in database instability and potential service disruption. Attackers could potentially exploit this weakness by crafting malicious sort patterns that trigger the invariant failure condition, leading to denial of service or data corruption scenarios. The vulnerability affects MongoDB's core query processing pipeline and could be leveraged in broader exploitation campaigns targeting database systems.
Mitigation strategies should focus on implementing comprehensive input validation for sort patterns during query planning, ensuring all BSON expression types including meta expressions are properly handled. Organizations should apply the latest security patches from MongoDB and consider implementing additional monitoring for unusual query patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-252, which addresses improper handling of exceptional conditions, and could potentially map to ATT&CK technique T1059.002 for command and scripting interpreter usage in crafting malicious queries.