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

> An active man-in-the-middle attacker can bypass TLS hostname verification to capture cleartext database passwords during authentication.

- **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:** No
- **Published:** 9 Oct 2026
- **Updated:** 9 Oct 2026
- **Also known as:** BELL-CVE-2026-107819, GHSA-fmq9-qjxj-qpf7, UBUNTU-CVE-2026-107819

## What is CVE-2026-107819?

CVE-2026-107819 is a medium-severity vulnerability in MariaDB server, published on 9 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-297 (Improper Validation of Certificate with Host Mismatch)

## Which versions are affected by CVE-2026-107819?


## How do I fix CVE-2026-107819?

No fix has been published for CVE-2026-107819 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-107819 being exploited?

There is no known exploitation of CVE-2026-107819 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-107819 and fix it if it is affected.

What it is: CVE-2026-107819 is a medium-severity vulnerability in MariaDB server, published on 9 Oct 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-2026-107819 in the wild and no public exploit code.

Affected product: MariaDB server. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-107819/ (Markdown: https://insights.sbomify.com/CVE-2026-107819/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-107819
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-107819
- OSV: https://osv.dev/vulnerability/CVE-2026-107819

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-107819/
Summaries are generated and may contain mistakes; the official description above is the record.