5.9
MEDIUM CVSS 3.1
CVE-2026-55858
MariaDB Connector/J: Inappropriate Encoding for Output Context in org.mariadb.jdbc:mariadb-java-client
Description

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, the connector encodes and decodes protocol text and performs client-side escaping under the assumption that the connection character set is UTF-8. The server can report a mid-session change to character_set_client through OK-packet session-state tracking, including a change caused by SET NAMES, a stored routine or trigger, server configuration, or a hostile server. If character_set_client changes to a non-UTF-8 value, the driver continues to read and write UTF-8 while the server interprets the same bytes under another encoding, causing silent data corruption and a client/server charset-confusion mismatch that can defeat byte-wise quoting or escaping. The fix accepts only utf8, utf8mb3, or utf8mb4 after initialization; any other value causes SQLException with SQLState 08000 and closes the connection. This issue is fixed in versions 2.7.14, 3.3.5, 3.4.3, and 3.5.9.

INFO

Published Date :

Aug. 28, 2026, 11:17 p.m.

Last Modified :

Aug. 28, 2026, 11:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-55858 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
Solution
Update MariaDB Connector/J to a fixed version to prevent data corruption due to character set mismatches.
  • Update MariaDB Connector/J to version 2.7.14 or later.
  • Update MariaDB Connector/J to version 3.3.5 or later.
  • Update MariaDB Connector/J to version 3.4.3 or later.
  • Update MariaDB Connector/J to version 3.5.9 or later.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-55858 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-55858 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-55858 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-55858 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Aug. 28, 2026

    Action Type Old Value New Value
    Added Description 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, the connector encodes and decodes protocol text and performs client-side escaping under the assumption that the connection character set is UTF-8. The server can report a mid-session change to character_set_client through OK-packet session-state tracking, including a change caused by SET NAMES, a stored routine or trigger, server configuration, or a hostile server. If character_set_client changes to a non-UTF-8 value, the driver continues to read and write UTF-8 while the server interprets the same bytes under another encoding, causing silent data corruption and a client/server charset-confusion mismatch that can defeat byte-wise quoting or escaping. The fix accepts only utf8, utf8mb3, or utf8mb4 after initialization; any other value causes SQLException with SQLState 08000 and closes the connection. This issue is fixed in versions 2.7.14, 3.3.5, 3.4.3, and 3.5.9.
    Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
    Added CWE CWE-838
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/55xxx/CVE-2026-55858.json">CVE-2026-55858</a>
    Added Reference https://github.com/mariadb-corporation/mariadb-connector-j/commit/300716bef1e1d0370a41be7863b88aa2d55fbb69
    Added Reference https://github.com/mariadb-corporation/mariadb-connector-j/commit/7b3c69221b5463ee03472654040b3f6b9e5329c7
    Added Reference https://github.com/mariadb-corporation/mariadb-connector-j/commit/8cfd9df697372ad4ed09fe87a34b34babb6d43d6
    Added Reference https://github.com/mariadb-corporation/mariadb-connector-j/commit/c555c9b477521be0c35c3a5461f9f46681553607
    Added Reference https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/2.7.14
    Added Reference https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/3.3.5
    Added Reference https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/3.4.3
    Added Reference https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/3.5.9
    Added Reference https://github.com/mariadb-corporation/mariadb-connector-j/security/advisories/GHSA-xvr9-35cr-46v9
    Added Reference https://jira.mariadb.org/browse/CONJ-1317
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.