CVE-2026-88412 in FalkorDB
Summary
by MITRE • 09/22/2026
An integer overflow in the _BulkInsert_ReadProperty component (/bulk_insert.c) of FalkorDB (Redis module) v4.20.1 allows attackers to cause a Denial of Service (DoS) via a crafted input.
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Analysis
by VulDB Data Team • 09/22/2026
The vulnerability identified as an integer overflow within the FalkorDB Redis module, specifically in the _BulkInsert_ReadProperty component located at /bulk_insert.c version 4.20.1, represents a critical memory safety issue that can be leveraged to disrupt service availability. Integer overflows occur when an arithmetic operation results in a value that exceeds the maximum limit of the data type used to store it. In this specific context, the flaw likely arises during the calculation or validation of buffer sizes or array indices associated with property parsing within bulk insert operations. When an attacker supplies crafted input containing values designed to trigger such an overflow, the resulting miscalculation can lead to incorrect memory allocation decisions or out-of-bounds access patterns. This deviation from expected behavior destabilizes the internal state of the database engine, ultimately causing a crash or hang that renders the service unavailable to legitimate users.
From a technical perspective, this vulnerability falls under CWE-190: Integer Overflow or Wraparound, which is categorized as an error in arithmetic operations where the result exceeds the capacity of the variable type. The exploitation vector typically involves sending specially crafted Redis commands that trigger the bulk insert functionality with malformed property data. Because FalkorDB operates as a module within the Redis ecosystem, it inherits certain architectural characteristics but also introduces its own parsing logic for graph and database structures. The _BulkInsert_ReadProperty function is responsible for interpreting incoming data streams to populate internal representations of properties. If this function fails to properly validate input ranges before performing arithmetic operations on them, an attacker can manipulate these values to cause the integer to wrap around or overflow into a small positive number or negative value. This misinterpretation often leads to heap corruption or segmentation faults when the system attempts to access memory based on the erroneous calculated size or index.
The operational impact of this vulnerability is primarily focused on Denial of Service, corresponding to MITRE ATT&CK technique T1499: Endpoint Denial of Service and potentially T1529: System Shutdown or Reboot if the crash leads to a persistent failure state in containerized environments. By repeatedly sending crafted requests that trigger the overflow condition, an attacker can exhaust system resources such as CPU cycles during error handling or memory buffers due to repeated allocation failures. This results in significant downtime for applications relying on FalkorDB for graph data storage and retrieval. Unlike vulnerabilities that allow remote code execution, this specific flaw is characterized by its ability to disrupt availability rather than compromise confidentiality or integrity directly, although the instability caused by heap corruption could theoretically be chained with other weaknesses to achieve more severe outcomes depending on the surrounding memory layout and exploitation context.
Mitigation strategies for this vulnerability involve both immediate patching and long-term architectural improvements. The most effective remediation is to upgrade FalkorDB to a version where the _BulkInsert_ReadProperty function has been patched to include rigorous input validation and bounds checking before any arithmetic operations are performed on user-supplied data. Developers should ensure that all integer calculations involving sizes, lengths, or indices use safe math libraries or explicit checks for overflow conditions prior to execution. Additionally, implementing strict rate limiting and request size restrictions at the network perimeter can help mitigate the impact by preventing attackers from flooding the service with crafted payloads. Enabling core dump analysis in production environments can also aid in detecting such crashes early, allowing administrators to identify exploitation attempts even if they do not immediately cause a total outage. Regular security audits focusing on memory safety and integer handling in C-based modules are essential to prevent similar vulnerabilities in future releases.