CVE-2026-55858
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.
Scoring
- Severity
- MEDIUM
- CVSS base score
- 5.9
- CVSS vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS probability
- 0.34%
- CWE
- CWE-838
- Published
- 2026-08-28
- Last modified
- 2026-09-01
Affected products
- mariadb-corporation mariadb-connector-j
- mariadb-corporation mariadb-connector-j
- mariadb-corporation mariadb-connector-j
- mariadb-corporation mariadb-connector-j
Weakness type
Related vulnerabilities
- CVE-2026-55859 — MariaDB Connector/R2DBC: Inappropriate Encoding for Output Context and Improper Encoding or Escaping of Output in org.mariadb:r2dbc-mariadb
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