CVE-2026-55860
mediumpriority · track · 0OT risk · elevatedEPSS 0.002 · 13 %ileDEUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (4)
Products and version ranges known to be affected.
advisories (2)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-3089MariaDB Connectors: Mehrere SchwachstellenDeutsch2026-08-30csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in MariaDB Connectors ausnutzen, um SQL-Injection-Angriffe durchzuführen, Sicherheitsmaßnahmen zu umgehen und Daten offenzulegen oder zu manipulieren.
- GHSA-c857-9x2m-cvh2org.mariadb:r2dbc-mariadb vulnerable to cleartext password disclosure to a man-in-the-middle server (clear-text auth plugins not gated on a secure transport)2026-08-28ghsa · osvUS
### Summary The connector does not gate clear-text password authentication plugins on transport encryption. A hostile or man-in-the-middle MariaDB server can request a clear-text plugin over an unencrypted (plain-TCP) connection, and the driver responds with the user's password in cleartext on the wire. ### Details The driver does not require a secure transport before using clear-text-password authentication plugins. A hostile or man-in-the-middle server can issue an AuthSwitchRequest naming mysql_clear_password or dialog (PAM) over a plain-TCP, unencrypted connection, and the driver replies with the user's password as cleartext bytes on the wire. The root cause is that the AuthenticationPlugin interface declares no capability for a plugin to require a secure connection. Because no such gate exists, clear-text plugins run regardless of whether the connection is encrypted. ### Impact The account password is transmitted in cleartext to the peer. An on-path attacker (MITM) who presents themselves as the server can capture the password during the authentication handshake. The disclosed credentials can subsequently be used to authenticate directly against the database server. ### Patches Fixed in 1.4.1. Clear-text authentication plugins (mysql_clear_password, dialog/PAM) now require a secure connection: the AuthenticationPlugin contract can declare that a plugin requires a secure transport, and such plugins are permitted only over an encrypted connection. Upgrade to 1.4.1 or later. ### Workarounds Until you can upgrade, configure certificate verification explicitly: provide the server/CA certificate and use a verifying SSL mode (e.g. VERIFY_CA / VERIFY_FULL) so the connection is encrypted and the server's identity is established before credentials are sent. ### Credit Reported by Yalguun Tumenkhuu ([@fg0x0](https://github.com/fg0x0/)).
sources
Which sources assert this record, and when.
references (5) nvd
External citations — patches, advisories, analysis.
- https://github.com/mariadb-corporation/mariadb-connector-r2dbc/commit/be786603ec5530414996d2396157013e095b320a
- https://github.com/mariadb-corporation/mariadb-connector-r2dbc/releases/tag/1.4.1
- https://github.com/mariadb-corporation/mariadb-connector-r2dbc/security/advisories/GHSA-c857-9x2m-cvh2
- https://hackerone.com/reports/3784556
- https://jira.mariadb.org/browse/R2DBC-115
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