CVE-2026-107821: CWE-1285: Improper Validation of Specified Index, Position, or Offset in Input in MariaDB server

CVE-2026-107821 is a vulnerability in MariaDB server where insufficient validation of counts, offsets, lengths, and field boundaries in FRM metadata occurs while opening binary FRM files. This improper validation can be exploited by an attacker who can place a maliciously crafted FRM file in the data directory, triggering out-of-bounds memory access that may result in server crashes or potentially arbitrary code execution. The vulnerability affects multiple MariaDB versions starting from 10.6.1 through various branches up to but excluding the fixed versions 10.6.28, 10.11.19, 11.4.13, 11.8.9, 12.3.3, and 13.0.2. The CVSS v3.1 score is 8.0, indicating high severity with network attack vector, high privileges required, no user interaction, and impact on confidentiality, integrity, and availability.

An attacker with the ability to place a crafted FRM file in the MariaDB data directory can exploit this vulnerability to cause out-of-bounds reads or writes. This can lead to server crashes (denial of service) or potentially arbitrary code execution, compromising the confidentiality, integrity, and availability of the database server.

This vulnerability is fixed in MariaDB versions 10.6.28, 10.11.19, 11.4.13, 11.8.9, 12.3.3, and 13.0.2. Users should upgrade to these or later versions to remediate the issue. No other mitigation or temporary workaround is indicated.