org.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)

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-55860: 0.23% estimated exploitation activity in the next 30 days; percentile 13.64 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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 mysqlclearpassword 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…

Published by the source

28 Aug 2026, 22:50 UTC

Last modified by the source

28 Aug 2026, 23:10 UTC

Source last checked

26 Oct 2026, 16:55 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-c857-9x2m-cvh2

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-c857-9x2m-cvh2

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# Patch Next advisory brief: CVE-2026-55860

Advisory: org.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)
IDs: CVE-2026-55860, GHSA-c857-9x2m-cvh2
Record: https://patchnext.com/advisories/cve-2026-55860 (revision 2, source checked 26 Oct 2026, 16:55 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.mariadb:r2dbc-mariadb 1.4.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.mariadb:r2dbc-mariadb: affected < 1.4.1; fixed in 1.4.1

## Suggested inspection (read-only)
- Maven org.mariadb:r2dbc-mariadb: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.mariadb:r2dbc-mariadb.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-c857-9x2m-cvh2 (OSV record GHSA-c857-9x2m-cvh2 lists affected ranges: Maven org.mariadb:r2dbc-mariadb >=0 <1.4.1 (fixed))
- Verified: https://github.com/advisories/GHSA-c857-9x2m-cvh2 (GitHub-reviewed advisory GHSA-c857-9x2m-cvh2 lists affected ranges: Maven org.mariadb:r2dbc-mariadb >=0 <1.4.1)

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