Vulnerability · Published Oct 16, 2026 · Assigned by GitHub_M

CVE-2026-85746MariaDB: Out-of-bound buffer write on in `ST_AsText` of nested GeometryCollections

Critical 9.9

In plain English

A critical-severity out-of-bounds write in server from MariaDB. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.0% (higher than 62% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.9Critical

Exploit odds (30 days)1.0%top 37.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

MariaDB server is a community developed fork of MySQL server. From 10.6.1 until 10.6.28, 10.11.19, 11.4.13, 11.8.9, 12.3.3, and 13.0.2, ST_AsText can write beyond an allocated output buffer when converting deeply nested GeometryCollections because recursive WKT serialization does not account for bytes consumed or reserve sufficient space. A low-privileged remote attacker can submit a specially crafted GIS object to corrupt memory and potentially achieve code execution when combined with another vulnerability. This issue is fixed in versions 10.6.28, 10.11.19, 11.4.13, 11.8.9, 12.3.3, and 13.0.2.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	mariadb	no fix listed	DEBIAN-CVE-2026-85746
Debian:13	mariadb	no fix listed	DEBIAN-CVE-2026-85746
Debian:14	mariadb	1:11.8.9+ds-1	DEBIAN-CVE-2026-85746
Ubuntu:24.04:LTS	mariadb	no fix listed	UBUNTU-CVE-2026-85746
Ubuntu:26.04:LTS	mariadb	no fix listed	UBUNTU-CVE-2026-85746
Ubuntu:26.10	mariadb	no fix listed	UBUNTU-CVE-2026-85746
Ubuntu:22.04:LTS	mariadb-10.6	no fix listed	UBUNTU-CVE-2026-85746

Affected products (as reported)

Vendor	Product	Versions
MariaDB	server	>= 10.6.1, < 10.6.28>= 10.11.1, < 10.11.19>= 11.4.1, < 11.4.13>= 11.8.1, < 11.8.9>= 12.3.1, < 12.3.3>= 13.0.1, < 13.0.2

Weakness: CWE-787 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

References

https://github.com/MariaDB/server/security/advisories/GHSA-8fvj-c57c-pggx x_refsource_CONFIRM
https://github.com/MariaDB/server/commit/5c04ca5524385356ff7cf84974a7d491974c1f85 x_refsource_MISC
https://github.com/MariaDB/server/releases/tag/mariadb-10.11.19 x_refsource_MISC
https://github.com/MariaDB/server/releases/tag/mariadb-10.6.28 x_refsource_MISC
https://github.com/MariaDB/server/releases/tag/mariadb-11.4.13 x_refsource_MISC
https://github.com/MariaDB/server/releases/tag/mariadb-11.8.9 x_refsource_MISC
https://github.com/MariaDB/server/releases/tag/mariadb-12.3.3 x_refsource_MISC
https://github.com/MariaDB/server/releases/tag/mariadb-13.0.2 x_refsource_MISC
https://jira.mariadb.org/browse/MDEV-40329 x_refsource_MISC