CVE-2026-55857
Description
A flaw was found in MariaDB Connector/J. A remote attacker or a man-in-the-middle server can exploit a vulnerability in the PAM dialog authentication mechanism. This flaw allows the attacker to coerce the connector into transmitting account passwords over an insecure connection when default configurations are used. Consequently, the user's password can be intercepted in cleartext, leading to sensitive information disclosure.
Statement
MariaDB Connector/J (org.mariadb.jdbc:mariadb-java-client) can be coerced by a hostile or man-in-the-middle server into performing PAM 'dialog' authentication over an unencrypted connection, transmitting the account password in cleartext. The affected path (SendPamAuthPacketFactory/SendPamAuthPacket) does not require secure transport and is reachable under the default configuration (sslMode=DISABLE, restrictedAuth unset). Verified TLS (sslMode=verify-ca or verify-full) and local Unix-socket connections are not exposed. Red Hat rates the impact of this flaw as Moderate because exploitation requires a man-in-the-middle network position and a plaintext connection.
Mitigation
Connect using sslMode=verify-full (or verify-ca) with a properly configured server certificate and trust store, or use a local Unix socket, so the connector never negotiates PAM dialog authentication over cleartext. Setting restrictedAuth to exclude the dialog/mysql_clear_password plugins also prevents disclosure. A fixed MariaDB Connector/J (2.7.14, 3.3.5, 3.4.3, or 3.5.9, as appropriate for the branch in use) additionally addresses the issue.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.9 | N/A | 5.9 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
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