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)

MEDIUM
5.9
CVSS Score
Published: August 28, 2026 at 10:50 PM UTC
Updated: September 8, 2026 at 09:19 PM UTC
2 products affected across 2 vendorsR2DBC MariadbConnector/R2DBC

Using mariadb-connector-r2dbc by mariadb-corporation?

Get instant alerts when new vulnerabilities affect mariadb-connector-r2dbc - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
MEDIUM5.9
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.4.1
Affected range stops below 1.4.1, so it looks safe — our inference, not a vendor statement
v < 1.4.1
Affected range stops below 1.4.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.9MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-319CWE-522

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card