CVE-2026-55859

MariaDB Connector/R2DBC: Inappropriate Encoding for Output Context and Improper Encoding or Escaping of Output in org.mariadb:r2dbc-mariadb

Published Aug 28, 2026 CVSS 3.1 · 5.9 Medium EPSS < 1% KEV · Not listed
Description
MariaDB Connector/R2DBC is a non-blocking MariaDB and MySQL client implemented in Java. Prior to 1.4.1, org.mariadb:r2dbc-mariadb encodes and decodes all character data under the assumption that the connection character set is UTF-8. A server can announce a mid-session change to character_set_client through the OK-packet session-state-tracking mechanism, including through SET NAMES executed by a stored routine or trigger, server configuration, or a hostile or man-in-the-middle server. If the new character set is not UTF-8, the driver continues to exchange UTF-8 while the server interprets the same bytes under a different 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 raises R2dbcNonTransientResourceException with SQLState 08000 and closes the connection. This issue is fixed in version 1.4.1.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-5rqc-86vf-g8r2 org.mariadb:r2dbc-mariadb has Inappropriate Encoding for Output Context and Improper Encoding or Escaping of Output
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Mariadb-corporation
Mariadb-corporation mariadb-connector-r2dbc
Org.mariadb
Org.mariadb r2dbc-mariadb
Vendors & Products Mariadb-corporation
Mariadb-corporation mariadb-connector-r2dbc
Org.mariadb
Org.mariadb r2dbc-mariadb
Type Values Removed Values Added
Description MariaDB Connector/R2DBC is a non-blocking MariaDB and MySQL client implemented in Java. Prior to 1.4.1, org.mariadb:r2dbc-mariadb encodes and decodes all character data under the assumption that the connection character set is UTF-8. A server can announce a mid-session change to character_set_client through the OK-packet session-state-tracking mechanism, including through SET NAMES executed by a stored routine or trigger, server configuration, or a hostile or man-in-the-middle server. If the new character set is not UTF-8, the driver continues to exchange UTF-8 while the server interprets the same bytes under a different 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 raises R2dbcNonTransientResourceException with SQLState 08000 and closes the connection. This issue is fixed in version 1.4.1.
Title MariaDB Connector/R2DBC: Inappropriate Encoding for Output Context and Improper Encoding or Escaping of Output in org.mariadb:r2dbc-mariadb
Weaknesses CWE-116
CWE-838
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Aug 31, 2026, 6:53 PM
Reserved
Jun 17, 2026, 4:44 PM
Status
Awaiting Analysis
Published
Aug 28, 2026, 11:17 PM
Modified
Sep 8, 2026, 9:08 PM