CVE-2026-55860
MariaDB Connector/R2DBC: Cleartext password disclosure to a man-in-the-middle server (clear-text auth plugins not gated on a secure transport)
- State
- Published
- Severity
- 5.9 Medium
- Published
- Aug 28, 2026
- Updated
- Aug 31, 2026
- Reserved
- Jun 17, 2026
Description
MariaDB Connector/R2DBC is a non-blocking MariaDB and MySQL client implemented in Java. Prior to 1.4.1, org.mariadb:r2dbc-mariadb does not gate clear-text password authentication plugins on transport encryption because the AuthenticationPlugin interface has no capability for a plugin to require a secure connection. A hostile or man-in-the-middle MariaDB server can send an AuthSwitchRequest naming mysql_clear_password or dialog (PAM) over a plain-TCP unencrypted connection, and AuthenticationFlow permits ClearPasswordPluginFlow or PamPluginFlow to return the user's password as cleartext bytes on the wire. The disclosed credentials can subsequently be used to authenticate directly to the database server. This issue is fixed in version 1.4.1.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 5.9 Medium | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N | GitHub_M |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
mariadb-connector-r2dbcmariadb-corporation |
|
r2dbc-mariadborg.mariadb |
|
References
- https://github.com/mariadb-corporation/mariadb-connector-r2dbc/security/advisories/GHSA-c857-9x2m-cvh2
- https://github.com/mariadb-corporation/mariadb-connector-r2dbc/commit/be786603ec5530414996d2396157013e095b320a
- https://hackerone.com/reports/3784556
- https://github.com/mariadb-corporation/mariadb-connector-r2dbc/releases/tag/1.4.1
- https://jira.mariadb.org/browse/R2DBC-115
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