CVE-2026-55857 mariadb-corporation CVE debrief

Who should care

Defenders and administrators using MariaDB Connector/J in Java applications should verify exposure and upgrade to fixed versions. This includes reviewing and adjusting sslMode and restrictedAuth configurations to prevent cleartext password transmission. Properly verified TLS and local Unix sockets are not exposed to this transport vector. Defenders should prioritize verifying exposure and upgrading to fixed versions 2.7.14, 3.3.5, 3.4.3, or 3.5.9.

Why it matters

CVE-2026-55857 allows account passwords to be transmitted over insecure connections in MariaDB Connector/J, requiring defenders to verify exposure and upgrade to fixed versions.

• Password transmission over insecure connections can lead to unauthorized access.
• Defenders should verify exposure and upgrade to fixed versions to prevent cleartext password transmission.
• Properly verified TLS and local Unix sockets are not exposed to this transport vector.

Technical summary

MariaDB Connector/J is vulnerable to transmitting account passwords over insecure connections due to improper configuration of the PAM dialog authentication. The issue is fixed in versions 2.7.14, 3.3.5, 3.4.3, and 3.5.9. The mysql_clear_password plugin is gated behind a secure transport, but the sibling PAM handler SendPamAuthPacketFactory, named dialog by the server, does not declare that requirement and inherits the default secure-required value false; older branches implement the same affected behavior in SendPamAuthPacket. A hostile or man-in-the-middle server can send an Authentication Switch Request for dialog over plain TCP, causing the driver to return the user's password in cleartext when sslMode=DIS

Defensive priority

Defenders should prioritize verifying exposure and upgrading to fixed versions 2.7.14, 3.3.5, 3.4.3, or 3.5.9.

Recommended defensive actions

• Verify exposure by checking current MariaDB Connector/J versions and configurations.
• Upgrade to fixed versions 2.7.14, 3.3.5, 3.4.3, or 3.5.9.
• Review and adjust sslMode and restrictedAuth configurations to prevent cleartext password transmission.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The CVE record and source references indicate that MariaDB Connector/J is vulnerable to transmitting account passwords over insecure connections due to improper configuration of the PAM dialog authentication. The issue is fixed in versions 2.7.14, 3.3.5, 3.4.3, and 3.5.9.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.