Executive Summary
A critical vulnerability, CVE-2026-32710, has been identified in MariaDB's JSON schema validation logic. Discovered by Xint Code and demonstrated at ZeroDay.Cloud 2025, the flaw allows any authenticated user—regardless of privilege level—to trigger a heap buffer overflow by supplying a specially crafted JSON string. This can be weaponized to achieve full remote code execution (RCE) on the database host.
The attack chain involves three sophisticated stages: using the overflow to corrupt session metadata for superuser privilege escalation, leaking memory addresses via `/proc/self/maps` to bypass ASLR, and finally overwriting global pointers to load a malicious shared library. Because the vulnerable function is built-in and requires no special grants, any user capable of establishing a SQL session (including through SQL injection or stolen application credentials) can exploit this vulnerability.
MariaDB released patches on February 4, 2026. Organizations running affected versions should prioritize upgrading to 11.4.10 or 11.8.6 immediately, as the bug poses a significant risk to multi-tenant environments and internet-exposed database instances.