Improper output encoding in mariadb-connector-r2dbc
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.
Summary
MariaDB Connector/R2DBC is a non-blocking MariaDB and MySQL client implemented in Java. Prior to 1.4.1, org.mariadb:r2dbc-mariadb encodes and decodes all character data under the assumption that the connection character set is UTF-8. A server can announce a mid-session change to character_set_client through the OK-packet session-state-tracking mechanism, including through SET NAMES executed by a stored routine or trigger, server configuration, or a hostile or man-in-the-middle server. If the new character set is not UTF-8, the driver continues to exchange UTF-8 while the server interprets the same bytes under a different encoding, causing silent data corruption and a client/server charset-confusion mismatch that can defeat byte-wise quoting or escaping. The fix accepts only utf8, utf8mb3, or utf8mb4 after initialization; any other value raises R2dbcNonTransientResourceException with SQLState 08000 and closes the connection. This issue is fixed in version 1.4.1.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| MariaDB | mariadb-connector-r2dbc | before 1.4.1 | 1.4.1 | Patch available | CNA |
| org.mariadb | r2dbc-mariadb | before 1.4.1 | 1.4.1 | Patch available | CNA |
| — | org.mariadb:r2dbc-mariadb (Maven) | before 1.4.1 | 1.4.1 | Patch available | GHSA-5rqc-86vf-g8r2 |
- mariadb-connector-r2dbc VendorMariaDB Affected before 1.4.1 Fixed in 1.4.1 Patch available CNA
- r2dbc-mariadb Vendororg.mariadb Affected before 1.4.1 Fixed in 1.4.1 Patch available CNA
- org.mariadb:r2dbc-mariadb (Maven) Vendor— Affected before 1.4.1 Fixed in 1.4.1 Patch available GHSA-5rqc-86vf-g8r2
Remediation
- Fix · CNA mariadb-connector-r2dbc (mariadb-corporation) Fixed in 1.4.1
- Fix · CNA r2dbc-mariadb (org.mariadb) Fixed in 1.4.1
- Fix · GHSA-5rqc-86vf-g8r2 org.mariadb:r2dbc-mariadb (Maven) Fixed in 1.4.1 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-55859
- 2026-10-03 Alias added: GHSA-5rqc-86vf-g8r2
References
Other 5
- https://github.com/mariadb-corporation/mariadb-connector-r2dbc/security/advisories/GHSA-5rqc-86vf-g8r2
- https://github.com/mariadb-corporation/mariadb-connector-r2dbc/commit/38bad9afebc6c581a853656a42f9ebf403b1b1b7
- https://github.com/mariadb-corporation/mariadb-connector-r2dbc/releases/tag/1.4.1
- https://jira.mariadb.org/browse/R2DBC-124
- https://github.com/mariadb-corporation/mariadb-connector-r2dbc
More MariaDB vulnerabilities
- TI-2023-11776 MariaDB v10.5 was discovered to contain a remote code execution (RCE) vulnerability via… CVSS 3.1CRITICAL 9.8
- TI-2016-05707 Oracle MySQL through 5.5.52, 5.6.x through 5.6.33, and 5.7.x through 5.7.15; MariaDB… CVSS 3.0CRITICAL 9.8
- TI-2022-00687 Infinite loop in BN_mod_sqrt() reachable when parsing certificates CVSS 3.1HIGH 7.5
- TI-2014-00217 OpenSSL before 0.9.8za, 1.0.0 before 1.0.0m, and 1.0.1 before 1.0.1h does not properly… CVSS 3.1HIGH 7.4
- TI-2014-00188 The dtls1_reassemble_fragment function in d1_both.c in OpenSSL before 0.9.8za, 1.0.0… CVSS 2.0MEDIUM 6.8
- TI-2018-15259 zlib before 1.2.12 allows memory corruption when deflating (i.e., when compressing) if… CVSS 3.1HIGH 7.5
Sources
- CVE-2026-55859 · CVE Program
- CVE-2026-55859 · NVD
- FIRST EPSS
- GHSA-5rqc-86vf-g8r2 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences