CVE-2026-55858: Mariadb java client Mariadb-java-client Has Inappropriate Encoding For Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-xvr9-35cr-46v9",
  "modified" : "2026-08-28T22:47:19Z",
  "published" : "2026-08-28T22:47:19Z",
  "aliases" : [ "CVE-2026-55858" ],
  "summary" : "org.mariadb.jdbc:mariadb-java-client has Inappropriate Encoding for Output Context",
  "details" : "### Summary\n\nThe connector encodes and decodes all character data assuming the connection character set is UTF-8. A server can change character_set_client mid-session to a non-UTF-8 charset, after which the driver and server interpret the same bytes under different encodings, causing silent data corruption and a client/server charset-confusion mismatch.\n\n### Details\n\nThe driver encodes and decodes all character data on the assumption that the connection character set is UTF-8. \nCharset can be changed by commands like SET NAMES... commands.\n\nIf the new charset is not UTF-8, the driver continues to read and write UTF-8 while the server interprets the same bytes under a different encoding. The result is silent data corruption and a client/server charset-confusion mismatch. Charset confusion of this kind is also the primitive that can defeat byte-wise quoting/escaping when client and server disagree on a multi-byte encoding.\n\n### Impact\n\nSilent data corruption and a client/server encoding mismatch once the connection's charset diverges from UTF-8. Because the mismatch undermines the assumption that quoting/escaping operates on UTF-8 bytes, it belongs to the charset-confusion class that can lead to SQL injection.\n\n### Patches\n\nFixed in 2.7.14, 3.3.5, 3.4.3, and 3.5.9. Upgrade to the patched release on your branch (3.5.x → 3.5.9, 3.4.x → 3.4.3, 3.0/3.1/3.2/3.3.x → 3.3.5, 2.x → 2.7.14). Once the connection is fully initialized, any subsequent charset change to a value that is not utf8 / utf8mb3 / utf8mb4 is rejected: the driver raises a SQLException with SQLState 08000 (connection exception) and closes the connection rather than continuing to exchange data under a mismatched encoding.\n\n### Workarounds\n\nThere is no reliable application-level workaround.\n\n### Credit\n\nReported by Yalguun Tumenkhuu ([@fg0x0](https://github.com/fg0x0/)).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.mariadb.jdbc:mariadb-java-client"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.7.14"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.mariadb.jdbc:mariadb-java-client"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.0.0"
      }, {
        "fixed" : "3.3.5"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.mariadb.jdbc:mariadb-java-client"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.4.0"
      }, {
        "fixed" : "3.4.3"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.mariadb.jdbc:mariadb-java-client"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.5.0"
      }, {
        "fixed" : "3.5.9"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/mariadb-corporation/mariadb-connector-j/security/advisories/GHSA-xvr9-35cr-46v9"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mariadb-corporation/mariadb-connector-j/commit/300716bef1e1d0370a41be7863b88aa2d55fbb69"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mariadb-corporation/mariadb-connector-j/commit/7b3c69221b5463ee03472654040b3f6b9e5329c7"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mariadb-corporation/mariadb-connector-j/commit/8cfd9df697372ad4ed09fe87a34b34babb6d43d6"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mariadb-corporation/mariadb-connector-j/commit/c555c9b477521be0c35c3a5461f9f46681553607"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/mariadb-corporation/mariadb-connector-j"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/2.7.14"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/3.3.5"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/3.4.3"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/3.5.9"
  }, {
    "type" : "WEB",
    "url" : "https://jira.mariadb.org/browse/CONJ-1317"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-838" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-28T22:47:19Z",
    "nvd_published_at" : null
  }
}