MariaDB Corporation MariaDB Connector/J up to 2.7.13/3.3.4/3.4.2/3.5.8 Initial Handshake HandshakeResponse.encode certificate validation

Summaryinfo

A vulnerability identified as problematic has been detected in MariaDB Corporation MariaDB Connector and J up to 2.7.13/3.3.4/3.4.2/3.5.8. Affected by this vulnerability is the function HandshakeResponse.encode of the component Initial Handshake. This manipulation causes certificate validation. The identification of this vulnerability is CVE-2026-55856. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in MariaDB Corporation MariaDB Connector and J up to 2.7.13/3.3.4/3.4.2/3.5.8. It has been declared as problematic. Affected by this vulnerability is the function HandshakeResponse.encode of the component Initial Handshake. The manipulation with an unknown input leads to a certificate validation vulnerability. The CWE definition for the vulnerability is CWE-295. The product does not validate, or incorrectly validates, a certificate. As an impact it is known to affect integrity. The summary by CVE is:

MariaDB Connector/J is used to connect applications developed in Java to MariaDB and MySQL databases. Prior to 2.7.14, 3.3.5, 3.4.3, and 3.5.9, when a Java application connects with sslMode=verify-full or sslMode=verify-ca, supplies a password, and does not configure serverSslCert or trustStore, Connector/J can accept an untrusted self-signed certificate through the fallbackToSystemTrustStore=true ephemeral trust manager and record its certFingerprint for later identity binding. The OK-packet and authentication-switch paths enforce the certificate fingerprint, but the initial-handshake path does not. HandshakeResponse.encode() can therefore build and send a mysql_clear_password response before checking certFingerprint != null && !isMitMProof(), sslMode, or whether the authentication plugin is resistant to a man-in-the-middle, and the initial path also bypasses restrictedAuth. An active man-in-the-middle or hostile server can present a self-signed certificate, claim to be MariaDB, select mysql_clear_password as the initial authentication plugin, and receive the full database password before the connection is rejected. This issue is fixed in versions 2.7.14, 3.3.5, 3.4.3, and 3.5.9.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-55856 since 06/17/2026. The exploitation appears to be difficult. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1587.003 according to MITRE ATT&CK.

Upgrading to version 2.7.14, 3.3.5, 3.4.3 or 3.5.9 eliminates this vulnerability.

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Productinfo

Type

• Database Software

Vendor

• MariaDB Corporation

Name

• J
• MariaDB Connector

Version

• 2.7.0
• 2.7.1
• 2.7.2
• 2.7.3
• 2.7.4
• 2.7.5
• 2.7.6
• 2.7.7
• 2.7.8
• 2.7.9
• 2.7.10
• 2.7.11
• 2.7.12
• 2.7.13
• 3.3.0
• 3.3.1
• 3.3.2
• 3.3.3
• 3.3.4
• 3.4.0
• 3.4.1
• 3.4.2
• 3.5.0
• 3.5.1
• 3.5.2
• 3.5.3
• 3.5.4
• 3.5.5
• 3.5.6
• 3.5.7
• 3.5.8

License

• open-source

CPE 2.3info

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CPE 2.2info

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