CVE-2026-55860: Credential Exposure (CVSS 5.9)

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.

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CVSS v3.1 Score

5.9

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS — Exploit Prediction

0.0015

Probability of exploitation

0.05%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-319 CWE-319

CWE-522 CWE-522

References

Other References

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

Frequently Asked Questions

What is CVE-2026-55860? +

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. It has a CVSS v3.1 base score of 5.9 (MEDIUM).

How severe is CVE-2026-55860? +

CVE-2026-55860 has a CVSS v3.1 score of 5.9 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0015, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-55860? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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