CVE-2026-85745 in MariaDB
Summary
by MITRE • 10/16/2026
MariaDB server is a community developed fork of MySQL server. From 10.6.1 until 10.6.28, 10.11.19, 11.4.13, 11.8.9, 12.3.3, and 13.0.2, ST_Area reads beyond the allocated buffer when processing invalid WKB for a MultiPolygon because the multi-polygon parser advances past a nested geometry header without first verifying enough input remains. A low-privileged remote attacker can supply malformed spatial data to disclose memory useful for bypassing ASLR as part of a multi-vulnerability chain. This issue is fixed in versions 10.6.28, 10.11.19, 11.4.13, 11.8.9, 12.3.3, and 13.0.2.
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Analysis
by VulDB Data Team • 10/16/2026
MariaDB server is a community-developed fork of the MySQL database management system that has been widely adopted for its open-source nature and compatibility with existing MySQL ecosystems. Within specific versions ranging from 10.6.1 up to but not including 10.6.28, as well as in branches 10.11 through 13.0 leading up to their respective patch releases, the database engine contains a critical memory safety flaw within its spatial data processing capabilities. This vulnerability specifically affects the ST_Area function when it attempts to calculate the area of geometric objects defined using Well-Known Binary (WKB) format. The core technical defect lies in the multi-polygon parser logic which fails to perform adequate bounds checking before advancing past nested geometry headers. When a malformed WKB payload is processed, particularly one containing invalid or truncated MultiPolygon structures, the parser proceeds to read memory locations beyond the initially allocated buffer boundaries. This behavior constitutes an out-of-bounds read vulnerability that allows data from adjacent memory regions to be exposed through standard query result sets or error messages returned by the database server.
The operational impact of this flaw is significant because it enables a low-privileged remote attacker who has access to the MariaDB instance to perform unauthorized information disclosure attacks. By crafting specific malicious spatial queries, an attacker can trigger the buffer over-read condition and extract sensitive memory contents from the server process. This leaked data often includes pointers, stack addresses, or heap metadata that are crucial for bypassing Address Space Layout Randomization (ASLR), a fundamental security mechanism designed to prevent exploitation of other vulnerabilities such as code injection attacks. Consequently, this vulnerability serves as a powerful enabler in multi-vulnerability chains where an attacker first leaks memory layout information and then exploits additional flaws like buffer overflows or use-after-free conditions with precise knowledge of the target environment's memory structure. The ability to bypass ASLR dramatically increases the success rate and reliability of subsequent exploitation attempts against the database server infrastructure.
From a classification perspective, this issue aligns closely with CWE-125 Out-of-bounds Read, which describes situations where software reads data past the end or before the beginning of intended buffer boundaries. In terms of offensive security frameworks, this vulnerability maps to ATT&CK technique T1074 Data Staged within Local System Processes and potentially supports lateral movement if combined with other exploits by facilitating privilege escalation through ASLR bypass techniques categorized under T1620 Reflective Code Loading or similar memory manipulation strategies. The root cause is a lack of rigorous input validation regarding the length fields present in WKB geometry headers, specifically failing to verify that sufficient input data remains before parsing nested structures within complex geometries like MultiPolygons.
Mitigation for this vulnerability requires immediate upgrading to patched versions including MariaDB 10.6.28, 10.11.19, 11.4.13, 11.8.9, 12.3.3, and 13.0.2 or later. Organizations running affected versions should prioritize patching to eliminate the memory safety flaw at its source. In environments where immediate upgrading is not feasible due to operational constraints, administrators can implement network-level access controls to restrict database connectivity strictly to trusted application servers using firewall rules or security groups. Additionally enabling strict input validation on the application layer before spatial data reaches the database engine can provide a secondary defense-in-depth measure by filtering out malformed WKB payloads before they trigger the vulnerable parser logic. Regular monitoring of database logs for unusual query patterns involving complex geometric operations may also aid in detecting attempted exploitation activities while patching efforts are underway.