CVE-2026-55858

Vulnerability Description

MariaDB Connector/J is used to connect applications developed in Java to MariaDB and MySQL databases. Prior to 2.7.14, 3.3.5, 3.4.3, and 3.5.9, the connector encodes and decodes protocol text and performs client-side escaping under the assumption that the connection character set is UTF-8. The server can report a mid-session change to character_set_client through OK-packet session-state tracking, including a change caused by SET NAMES, a stored routine or trigger, server configuration, or a hostile server. If character_set_client changes to a non-UTF-8 value, the driver continues to read and write UTF-8 while the server interprets the same bytes under another encoding, causing silent data corruption and a client/server charset-confusion mismatch that can defeat byte-wise quoting or escaping. The fix accepts only utf8, utf8mb3, or utf8mb4 after initialization; any other value causes SQLException with SQLState 08000 and closes the connection. This issue is fixed in versions 2.7.14, 3.3.5, 3.4.3, and 3.5.9.

CVSS Score

Related Weaknesses (CWE)

References

• https://github.com/mariadb-corporation/mariadb-connector-j/commit/300716bef1e1d0
• https://github.com/mariadb-corporation/mariadb-connector-j/commit/7b3c69221b5463
• https://github.com/mariadb-corporation/mariadb-connector-j/commit/8cfd9df697372a
• https://github.com/mariadb-corporation/mariadb-connector-j/commit/c555c9b477521b
• https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/2.7.14
• https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/3.3.5
• https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/3.4.3
• https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/3.5.9
• https://github.com/mariadb-corporation/mariadb-connector-j/security/advisories/G
• https://jira.mariadb.org/browse/CONJ-1317