Answer in brief
CVE-2026-55856 records a Medium severity (CVSS 5.9) vulnerability in MariaDB Connector/J: Cleartext password disclosure to a MITM on the initial-handshake. 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, < 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 |
| org.mariadb.jdbc:mariadb-java-clientmaven | >=0 <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
Sep 10, 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, when a Java application connects with sslMode=verify-full or sslMode=verify-ca, supplies a password, and does not configure serverSslCert or trustStore, Connector/J can accept an untrusted self-signed certificate through the fallbackToSystemTrustStore=true ephemeral trust manager and record its certFingerprint for later identity binding. The OK-packet and authentication-switch paths enforce the certificate fingerprint, but the initial-handshake path does not. HandshakeResponse.encode() can therefore build and send a mysql_clear_password response before checking certFingerprint != null && !isMitMProof(), sslMode, or whether the authentication plugin is resistant to a man-in-the-middle, and the initial path also bypasses restrictedAuth. An active man-in-the-middle or hostile server can present a self-signed certificate, claim to be MariaDB, select mysql_clear_password as the initial authentication plugin, and receive the full database password before the connection is rejected. 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.