Answer in brief
CVE-2026-55858 records a Medium severity (CVSS 5.9) vulnerability in MariaDB Connector/J: Inappropriate Encoding for Output Context in org.mariadb.jdbc:mariadb-java-client. The current sources do not mark it as known exploited. The current feed maps mariadb-corporation/mariadb-connector-j (generic), org.mariadb.jdbc:mariadb-java-client (maven), org.mariadb.jdbc:mariadb-java-client (maven), org.mariadb.jdbc:mariadb-java-client (maven) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.9. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps mariadb-corporation/mariadb-connector-j (generic), org.mariadb.jdbc:mariadb-java-client (maven), org.mariadb.jdbc:mariadb-java-client (maven), org.mariadb.jdbc:mariadb-java-client (maven) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| mariadb-corporation/mariadb-connector-jgeneric | < 2.7.14 || >= 3.0.0-alpha, < 3.3.5 || >= 3.4.0, < 3.4.3 || >= 3.5.0, < 3.5.9 | Not reported |
| org.mariadb.jdbc:mariadb-java-clientmaven | <2.7.14 | 2.7.14 |
| org.mariadb.jdbc:mariadb-java-clientmaven | >=3.0.0,<3.3.5 | 3.3.5 |
| org.mariadb.jdbc:mariadb-java-clientmaven | >=3.4.0,<3.4.3 | 3.4.3 |
| org.mariadb.jdbc:mariadb-java-clientmaven | >=3.5.0,<3.5.9 | 3.5.9 |
Published upstream
Aug 28, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 28, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 28, 2026
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.
Quoted source text, attributed separately from HOL analysis.