CVE-2026-55859
MEDIUMDescription
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.
How to fix
No published remediation has been found for this vulnerability's affected products yet.
Mitigation guidance may be in the linked vendor advisories in the References section below.
TridentStack Control tracks known vulnerabilities across your Windows, macOS, and Linux fleet and shows the fix as soon as one is published. See how it works
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Exploit Intelligence
Low risk: more likely to be exploited than 14% of all known CVEs.
References
Related Vulnerabilities
Other CWE-116 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2024-38475 | Critical | 9.1 | 100% | KEV | Fix |
| CVE-2022-36446 | Critical | 9.8 | 96% | - | Fix |
| CVE-2021-31806 | Medium | 6.5 | 96% | - | Fix |
| CVE-2022-30781 | High | 7.5 | 89% | - | Fix |
| CVE-2022-36099 | Critical | 9.9 | 76% | - | Fix |
| CVE-2022-36100 | Critical | 9.9 | 74% | - | Fix |
Common questions
How do I fix CVE-2026-55859?
No published fix for CVE-2026-55859 has been found yet. Check the linked vendor advisories for guidance as it becomes available.
Is CVE-2026-55859 being actively exploited?
Not that we know of. CVE-2026-55859 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.23% is the estimated probability that it will be exploited in the next 30 days. That is higher than 14% of all scored CVEs.
How severe is CVE-2026-55859?
CVE-2026-55859 has a CVSS v3 base score of 5.9, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
Embed a live status badge for CVE-2026-55859
Markdown
[](https://tridentstack.com/cve/CVE-2026-55859)HTML
<a href="https://tridentstack.com/cve/CVE-2026-55859"><img src="https://tridentstack.com/cve/badge/CVE-2026-55859.svg" alt="CVE-2026-55859"></a>Find and fix vulnerabilities across your fleet
TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-08-28.