CVE-2026-102523 in MariaDB
Summary
by MITRE • 11/05/2026
MariaDB server is a community developed fork of MySQL server. From 10.11.1 until 10.11.19, 11.4.13, 11.8.9, 12.3.3, and 13.0.2, ALTER TABLE ... CONVERT ... PARTITION does not apply filename encoding to user-specified partition names before using them in filesystem path construction. An authenticated database user can use a partition name requiring filename escaping to make the conversion operate on table files the user is not authorized to access, allowing unauthorized table reads or modifications. This issue is fixed in versions 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 • 11/05/2026
MariaDB server, a community-developed fork of the MySQL database management system, contains a critical security vulnerability affecting specific versions ranging from 10.11.1 through 10.11.18, as well as 11.4.12 and earlier, 11.8.8 and earlier, 12.3.2 and earlier, and 13.0.1 and earlier. The core of this issue lies in the handling of file system paths during table partitioning operations. Specifically, when an administrator or authorized user executes an ALTER TABLE statement that involves converting partitions, the database engine fails to properly sanitize or encode user-specified partition names before incorporating them into filesystem path constructions. This oversight creates a direct pathway for directory traversal attacks within the context of the MariaDB process privileges.
The technical flaw stems from insufficient validation of input data used in file system operations. When a user specifies a partition name that includes characters requiring escaping, such as backslashes or forward slashes depending on the operating system, these characters are not neutralized before being concatenated into the path string intended to locate table files. Consequently, an authenticated database user can manipulate this path structure to reference directories and files outside of the designated data directory for the specific table. This behavior effectively bypasses the logical access controls enforced by MariaDB at the SQL level, allowing the operation to target arbitrary file system locations accessible by the operating system account running the MariaDB service.
The operational impact of this vulnerability is severe, as it allows an authenticated user with ALTER TABLE privileges to perform unauthorized reads or modifications on table files they do not own or have permission to access within the database schema. By crafting a malicious partition name that escapes the intended directory boundary, an attacker can potentially overwrite critical system files, read sensitive data from other databases stored in adjacent directories, or corrupt unrelated table structures. This represents a significant breach of confidentiality and integrity, as it undermines the isolation guarantees provided by multi-tenant database environments where different users are expected to have strictly scoped access rights.
This vulnerability is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory, which describes flaws allowing attackers to access files outside of the intended directory through path manipulation techniques such as dot-dot-slash sequences or encoded variants thereof. In terms of offensive security frameworks, this aligns with ATT&CK technique T1083: File and Directory Discovery, where an adversary explores the file system to locate sensitive information, although in this specific case, it extends beyond mere discovery into active modification due to the write capabilities inherent in ALTER TABLE operations. The attack vector is local or network-based depending on how MariaDB is exposed, but requires authentication, placing it within the scope of authenticated attacks rather than remote code execution without credentials.
Mitigation strategies primarily involve upgrading to patched versions immediately. Users running affected releases must upgrade to version 10.11.19 or later for the 10.11 series, 11.4.13 or later for the 11.4 series, 11.8.9 or later for the 11.8 series, 12.3.3 or later for the 12.3 series, and 13.0.2 or later for the 13.0 series. These updates include fixes that ensure proper encoding and validation of partition names before they are used in file system operations. Additionally, organizations should enforce strict least-privilege principles by limiting ALTER TABLE permissions to only those users who absolutely require them, thereby reducing the attack surface available to potential insiders or compromised accounts. Regular auditing of database user privileges and monitoring for unusual file access patterns can also provide early detection indicators if an exploitation attempt occurs before patching is completed.