CVE-2026-55856MariaDB Connector/J: Cleartext password disclosure to a MITM on the initial-handshake
- 5.9MediumCVSS base score
- 0.44%Exploitation in 30 daysEPSS · top 61% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By GitHub_M
- 2 months later
· 2 months later
Published
- 3 days later
· 3 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N |
| NVDNVD · Awaiting Analysis | 3.1 | Medium5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.44% · top 61% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.9.
Affected products
mariadb-corporation · mariadb-connector-j
- affected < 2.7.14
- affected >= 3.0.0, < 3.3.5
- affected >= 3.4.0, < 3.4.3
- affected >= 3.5.0, < 3.5.9
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Mavenorg.mariadb.jdbc:mariadb-java-clientGHSA-g9jj-cgmh-9f38 (opens in a new tab)
References
References7
- https://github.com/mariadb-corporation/mariadb-connector-j/security/advisories/GHSA-g9jj-cgmh-9f38 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/mariadb-corporation/mariadb-connector-j/commit/149ec6a626376214966c01f42d48be1b80d06056 (opens in a new tab)x_refsource_MISC
- https://github.com/mariadb-corporation/mariadb-connector-j/commit/d90b9872322c76b05a48219be66bff1d33102f8a (opens in a new tab)x_refsource_MISC
- https://hackerone.com/reports/3777370 (opens in a new tab)x_refsource_MISC
- https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/3.4.3 (opens in a new tab)x_refsource_MISC
- https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/3.5.9 (opens in a new tab)x_refsource_MISC
- https://jira.mariadb.org/browse/CONJ-1325 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-68019 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-g9jj-cgmh-9f38 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-55856)Record last updated .