# CVE-2026-107816: MariaDB qc_info plugin out-of-bounds read on embedded null bytes

Source: https://junglewise.ai/threats/cve-2026-107816-mariadb-server-is-a-community-developed-fork-of-mysql-server  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-09. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-107816 · Severity: medium · CVSS 6.4 · Published 2026-10-09

MariaDB Server is a widely-used open-source database server. A flaw in the optional qc_info plugin causes it to mishandle database queries containing embedded null bytes; when the query cache is accessed afterwards, an attacker can read data from adjacent server memory or crash the database. This could lead to exposure of sensitive data or service outage.

Technologies: [Mariadb](https://junglewise.ai/threats/technologies/mariadb), [MariaDB Server](https://junglewise.ai/threats/technologies/mariadb-mariadb-server). Vendors: [Mariadb](https://junglewise.ai/threats/vendors/mariadb).

## Quick answers

**Is CVE-2026-107816 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-107816 being exploited in the wild.

**How severe is CVE-2026-107816?** Medium severity, with a CVSS score of 6.4, published 9 October 2026.

**Which products and versions are affected?** MariaDB Server 10.6.1 to 10.6.27, 10.11.x to 10.11.18, 11.4.x to 11.4.12, 11.8.x to 11.8.8, 12.3.x to 12.3.2, 13.0.x to 13.0.1.

**Is there a fix for CVE-2026-107816?** Yes: fixed in 10.6.28, 10.11.19, 11.4.13, 11.8.9, 12.3.3, 13.0.2. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-107816 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-107816?** Check whether you run Mariadb or MariaDB Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 10.6.28, 10.11.19, 11.4.13, 11.8.9, 12.3.3, 13.0.2

## Technical details

The qc_info plugin fails to properly validate the database name length when parsing queries cached in the query cache, leading to an out-of-bounds heap read. An attacker with the ability to execute queries can craft a query with embedded null bytes that, once cached, will cause out-of-bounds memory access when information_schema.query_cache_info is queried. The fix limits the parsed db_length to prevent reading beyond the actual database name extent.

## Affected products

- MariaDB MariaDB Server 10.6.1 to 10.6.27, 10.11.x to 10.11.18, 11.4.x to 11.4.12, 11.8.x to 11.8.8, 12.3.x to 12.3.2, 13.0.x to 13.0.1

## Timeline

- 2026-10-09: disclosed
- 2026-10-09: patched

## References

- [https://github.com/MariaDB/server/commit/0931994096b84ecc9ffc8eb3517c7e09e6e8631e](https://github.com/MariaDB/server/commit/0931994096b84ecc9ffc8eb3517c7e09e6e8631e)
- [https://github.com/MariaDB/server/releases/tag/mariadb-10.11.19](https://github.com/MariaDB/server/releases/tag/mariadb-10.11.19)

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