# CVE-2026-55857: MariaDB Connector/J: Cleartext Transmission of Sensitive Information and Insufficiently Protected Credentials

> A man-in-the-middle attacker can steal user passwords transmitted in cleartext by the MariaDB Connector/J driver during PAM authentication over insecure connections.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 28 Aug 2026
- **Updated:** 31 Aug 2026
- **Also known as:** CLEANSTART-2026-DB67213, CLEANSTART-2026-DR90917, CLEANSTART-2026-HN65934, CLEANSTART-2026-UR21896, ECHO-bfa8-1e82-e7b7, GHSA-qxvw-fvwx-5cp7, MINI-4w58-5fxv-m672, MINI-6fhx-fhp2-3q59, MINI-6jfx-637h-g42g, MINI-7qq7-w848-j84h, MINI-85qf-4p89-r9cv, MINI-8r5q-5426-6c9r, MINI-93rf-jg73-6w93, MINI-9pm2-58c6-cgqh, MINI-9x53-258c-3v8w, MINI-frrh-p5gh-pmrc, MINI-hxx9-cmx6-9jp8, MINI-mj37-hfqf-6h68, MINI-pc2m-vx6p-q287, MINI-pwcq-q9f7-6p85, MINI-vg23-2grg-xm8c

## What is CVE-2026-55857?

CVE-2026-55857 is a medium-severity vulnerability in mariadb-corporation mariadb-connector-j, published on 28 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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, PAM dialog authentication can be coerced into transmitting the account password over an insecure connection. The mysql_clear_password plugin is gated behind a secure transport, but the sibling PAM handler SendPamAuthPacketFactory, named dialog by the server, does not declare that requirement and inherits the default secure-required value false; older branches implement the same affected behavior in SendPamAuthPacket. A hostile or man-in-the-middle server can send an Authentication Switch Request for dialog over plain TCP, causing the driver to return the user's password in cleartext when sslMode=DISABLE and restrictedAuth=null, which is the default configuration. Properly verified TLS and local Unix sockets are not exposed to this transport vector. This issue is fixed in versions 2.7.14, 3.3.5, 3.4.3, and 3.5.9.

Weakness: CWE-522 (Insufficiently Protected Credentials), CWE-319 (Cleartext Transmission of Sensitive Information)

## Which versions are affected by CVE-2026-55857?

8 open source packages ship an affected version, including org.mariadb.jdbc:mariadb-java-client.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.mariadb.jdbc:mariadb-java-client` | Maven | All versions | 2.7.14 |
| `org.mariadb.jdbc:mariadb-java-client` | Maven | All versions | 2.7.14 |
| `org.mariadb.jdbc:mariadb-java-client` | Maven | From 3.0.0 | 3.3.5 |
| `org.mariadb.jdbc:mariadb-java-client` | Maven | From 3.0.0 | 3.3.5 |
| `org.mariadb.jdbc:mariadb-java-client` | Maven | From 3.4.0 | 3.4.3 |
| `org.mariadb.jdbc:mariadb-java-client` | Maven | From 3.4.0 | 3.4.3 |
| `org.mariadb.jdbc:mariadb-java-client` | Maven | From 3.5.0 | 3.5.9 |
| `org.mariadb.jdbc:mariadb-java-client` | Maven | From 3.5.0 | 3.5.9 |

## How do I fix CVE-2026-55857?

Upgrade org.mariadb.jdbc:mariadb-java-client to a fixed version for your release line: 2.7.14, 3.3.5, 3.4.3 or 3.5.9.

## Is CVE-2026-55857 being exploited?

There is no known exploitation of CVE-2026-55857 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55857 and fix it if it is affected.

What it is: CVE-2026-55857 is a medium-severity vulnerability in mariadb-corporation mariadb-connector-j, published on 28 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-55857 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.mariadb.jdbc:mariadb-java-client (Maven): affected all versions; fixed in 2.7.14
- org.mariadb.jdbc:mariadb-java-client (Maven): affected all versions; fixed in 2.7.14
- org.mariadb.jdbc:mariadb-java-client (Maven): affected from 3.0.0; fixed in 3.3.5
- org.mariadb.jdbc:mariadb-java-client (Maven): affected from 3.0.0; fixed in 3.3.5
- org.mariadb.jdbc:mariadb-java-client (Maven): affected from 3.4.0; fixed in 3.4.3
- org.mariadb.jdbc:mariadb-java-client (Maven): affected from 3.4.0; fixed in 3.4.3
- org.mariadb.jdbc:mariadb-java-client (Maven): affected from 3.5.0; fixed in 3.5.9
- org.mariadb.jdbc:mariadb-java-client (Maven): affected from 3.5.0; fixed in 3.5.9

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-55857/ (Markdown: https://insights.sbomify.com/CVE-2026-55857/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55857
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55857
- OSV: https://osv.dev/vulnerability/CVE-2026-55857

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-55857/
Summaries are generated and may contain mistakes; the official description above is the record.