# org.mariadb.jdbc:mariadb-java-client has Inappropriate Encoding for Output Context

Advisory record · `GHSA-xvr9-35cr-46v9`

- **Identifiers:** `GHSA-xvr9-35cr-46v9` · `CVE-2026-55858`
- **State:** Confirmed
- **Severity:** CVSS 5.9 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-838](https://cwe.mitre.org/data/definitions/838.html)
- **Tags:** [CWE-838](https://agentprime.io/advisories/tag/cwe-838.md)
- **Published:** 28 Aug 2026
- **Updated:** 10 Sept 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 28 Aug 2026, 22:47 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `org.mariadb.jdbc:mariadb-java-client` (Maven): affected `<2.7.14 || >=3.0.0, <3.3.5 || >=3.4.0, <3.4.3 || >=3.5.0, <3.5.9`; fixed in `2.7.14`, `3.3.5`, `3.4.3`, `3.5.9`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Versions of org.mariadb.jdbc:mariadb-java-client before 2.7.14, from 3.0.0 before 3.3.5, from 3.4.0 before 3.4.3, and from 3.5.0 before 3.5.9 are affected. The driver assumes UTF-8 for all character data, but a server can switch the session to a non-UTF-8 character set mid-session, causing silent data corruption and possibly SQL injection through charset confusion. Upgrade to 2.7.14, 3.3.5, 3.4.3, or 3.5.9 for your branch. The source states there is no reliable application-level workaround.

Written 2 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 5.9 Medium, CVSS 3.1: `CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0087, the 59th percentile, on 6 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:16 UTC: First seen by agentprime
- 31 Oct 2026, 14:16 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-xvr9-35cr-46v9)

## Sources

- [GitHub Advisory Database: GHSA-xvr9-35cr-46v9](https://github.com/advisories/GHSA-xvr9-35cr-46v9)
- [OSV: GHSA-xvr9-35cr-46v9](https://osv.dev/vulnerability/GHSA-xvr9-35cr-46v9)
- <https://github.com/mariadb-corporation/mariadb-connector-j/security/advisories/GHSA-xvr9-35cr-46v9>
- <https://github.com/mariadb-corporation/mariadb-connector-j/commit/300716bef1e1d0370a41be7863b88aa2d55fbb69>
- <https://github.com/mariadb-corporation/mariadb-connector-j/commit/7b3c69221b5463ee03472654040b3f6b9e5329c7>
- <https://github.com/mariadb-corporation/mariadb-connector-j/commit/8cfd9df697372ad4ed09fe87a34b34babb6d43d6>
- <https://github.com/mariadb-corporation/mariadb-connector-j/commit/c555c9b477521be0c35c3a5461f9f46681553607>
- <https://github.com/mariadb-corporation/mariadb-connector-j>
- <https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/2.7.14>
- <https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/3.3.5>
- <https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/3.4.3>
- <https://github.com/mariadb-corporation/mariadb-connector-j/releases/tag/3.5.9>
- <https://jira.mariadb.org/browse/CONJ-1317>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-xvr9-35cr-46v9>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-xvr9-35cr-46v9/>. Everything for agents: <https://agentprime.io/llms.txt>.