CVE-2026-55215: MariaDB Connector/Node.js: Connector leaks the cleartext password to an MitM despite `ssl: true`

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-28 · updated 2026-09-08
Weakness: CWE-295

Description

MariaDB Connector/Node.js is used to connect applications developed on Node.js to MariaDB and MySQL databases. Prior to versions 3.3.3, 3.4.6, and 3.5.3, when ssl is enabled without a pinned CA or server certificate, MariaDB Connector/Node.js sends credentials before completing certificate fingerprint validation. In lib/cmd/handshake/auth/handshake.js, a server that selects mysql_clear_password as the initial authentication plugin can receive the password before the post-TLS identity check. In lib/cmd/handshake/authentication.js, an authentication switch can evaluate the previous plugin instead of the requested target plugin, allowing mysql_clear_password to send the credential first. An active man-in-the-middle can present a self-signed certificate, capture the database password, and use it to authenticate directly even though the connector later rejects the server and closes the connection. This issue is fixed in versions 3.3.3, 3.4.6, and 3.5.3.

Affected products

mariadb-corporation mariadb-connector-nodejs: before 3.2.4

References

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