MariaDB Connector/J: Inappropriate Encoding for Output Context in org.mariadb.jdbc:mariadb-java-client

Summary

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.

Timeline

1. Aug 28, 2026, 10:46 PM UTCCVE published
2. Sep 1, 2026, 2:05 AM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: partial

3. Sep 1, 2026, 2:06 AM UTCRecord last updated

Affected versions

• mariadb-corporation mariadb-connector-j

  fixed in 2.7.14; From 3.0.0-alpha · fixed in 3.3.5; From 3.4.0 · fixed in 3.4.3; From 3.5.0 · fixed in 3.5.9

• org.mariadb.jdbc:mariadb-java-clientMaven

  fixed in 2.7.14

• org.mariadb.jdbc:mariadb-java-clientMaven

  From 3.0.0 · fixed in 3.3.5

• org.mariadb.jdbc:mariadb-java-clientMaven

  From 3.4.0 · fixed in 3.4.3

• org.mariadb.jdbc:mariadb-java-clientMaven

  From 3.5.0 · fixed in 3.5.9

References 10