# CVE-2026-85746: MariaDB ST_AsText buffer overflow in nested GeometryCollections

Source: https://junglewise.ai/threats/cve-2026-85746-mariadb-server-is-a-community-developed-fork-of-mysql-server-from  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-16. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-85746 · Severity: critical · CVSS 9.9 · Published 2026-10-16

MariaDB is a widely-used open-source database server that processes geographic and spatial data. A flaw in the ST_AsText function allows an attacker with database access to submit a specially crafted geographic object that corrupts memory, potentially leading to remote code execution on the database server.

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

## Quick answers

**Is CVE-2026-85746 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-85746 being exploited in the wild.

**How severe is CVE-2026-85746?** Critical severity, with a CVSS score of 9.9, published 16 October 2026.

**Which products and versions are affected?** MariaDB Server 10.6.1 to 10.6.27, 10.11.0 to 10.11.18, 11.4.0 to 11.4.12, 11.8.0 to 11.8.8, 12.3.0 to 12.3.2, 13.0.0 to 13.0.1.

**Is there a fix for CVE-2026-85746?** Yes: fixed in MariaDB Server 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-2026-85746 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-85746?** Check whether you run 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 MariaDB Server 10.6.28, 10.11.19, 11.4.13, 11.8.9, 12.3.3, 13.0.2

## Technical details

The ST_AsText function performs recursive WKT (Well-Known Text) serialization of GeometryCollections without properly accounting for bytes already written to the output buffer. This causes a heap buffer overflow when deeply nested geometry structures are converted. A low-privileged remote attacker can exploit this via a crafted GIS object to achieve memory corruption and potentially code execution, especially when combined with other vulnerabilities.

## Affected products

- MariaDB MariaDB Server 10.6.1 to 10.6.27, 10.11.0 to 10.11.18, 11.4.0 to 11.4.12, 11.8.0 to 11.8.8, 12.3.0 to 12.3.2, 13.0.0 to 13.0.1

## Timeline

- 2026-10-16: disclosed

## References

- [https://github.com/MariaDB/server/commit/5c04ca5524385356ff7cf84974a7d491974c1f85](https://github.com/MariaDB/server/commit/5c04ca5524385356ff7cf84974a7d491974c1f85)
- [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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