{"id":"CVE-2026-55856","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-55856","generatedAt":"2026-10-28T03:27:00.153Z","title":"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…","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, 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.","published":"2026-08-28T23:17:09.000Z","lastModified":"2026-09-08T21:08:37.000Z","status":"Awaiting Analysis","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":5.9,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"},"cwe":["CWE-522"],"affected":[],"epss":{"score":0.00443,"percentile":0.38236,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.44%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/mariadb-corporation/mariadb-connector-j/commit/149ec6a626376214966c01f42d48be1b80d06056","source":"security-advisories@github.com"},{"url":"https://github.com/mariadb-corporation/mariadb-connector-j/commit/d90b9872322c76b05a48219be66bff1d33102f8a","source":"security-advisories@github.com"},{"url":"https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/3.4.3","source":"security-advisories@github.com"},{"url":"https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/3.5.9","source":"security-advisories@github.com"},{"url":"https://github.com/mariadb-corporation/mariadb-connector-j/security/advisories/GHSA-g9jj-cgmh-9f38","source":"security-advisories@github.com"},{"url":"https://hackerone.com/reports/3777370","source":"security-advisories@github.com"},{"url":"https://jira.mariadb.org/browse/CONJ-1325","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-55856","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}