server: Use After Free
CVE-2026-85748 is a critical-severity use after free vulnerability in server from MariaDB, with a CVSS 3.1 base score of 9.9 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected server versions: >= 12.3.1, < 12.3.3; >= 13.0.1, < 13.0.2. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.18% chance of exploitation within 30 days, higher than 68% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Mariadb to 12.3.3 or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| MariaDB | server | >= 12.3.1, < 12.3.3; >= 13.0.1, < 13.0.2 | Not stated |
| MariaDB | Mariadb | 12.3.1 up to, but not including, 12.3.3; 13.0.1 | 12.3.3 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (github.com).
Official description
MariaDB server is a community developed fork of MySQL server. From 12.3.1 until 12.3.3 and 13.0.2, SYS_REFCURSOR handling is affected because cursor-array reallocation can leave stale references in routine contexts. A low-privileged attacker can open a large number of SYS_REFCURSORs and then fetch one to trigger a use-after-free that can enable remote code execution when combined with another vulnerability. This issue is fixed in versions 12.3.3 and 13.0.2.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
- jira.mariadb.org/browse/MDEV-40396Issue Tracking
- jira.mariadb.org/browse/MDEV-40639Issue Tracking
Other vulnerabilities in server
- 8.0 High severity
- 8.8 High severity
- 9.9 Critical severity
- 7.7 High severity
- 9.9 Critical severity
- 7.2 High severity
Recent Use After Free vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 9.8 Critical severity
- 8.1 High severity
Spotted an error? Tell us.