PatchSiren cyber security CVE debrief
CVE-2026-55860 MariaDB Corporation CVE debrief
CVE-2026-55860 debrief based on CVE Program and NVD records. The CVE record was published on 2026-08-28T23:17:09.153Z and has not been modified since then. The NVD entry is currently Awaiting Analysis. This vulnerability affects MariaDB Connector/R2DBC versions prior to 1.4.1, allowing clear-text password authentication plugins to be used over unencrypted connections. A hostile or man-in-the-middle MariaDB server can send an AuthSwitchRequest naming mysql_clear_password or dialog (PAM) over a plain-TCP unencrypted connection.
- Vendor
- MariaDB Corporation
- Product
- MariaDB Connector/R2DBC
- CVSS
- MEDIUM 5.9
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-08-28
- Original CVE updated
- 2026-09-08
- Advisory published
- 2026-08-28
- Advisory updated
- 2026-09-08
Who should care
Defenders responsible for MariaDB Connector/R2DBC deployments should assess the security of their database connections and verify exposure to this vulnerability. This includes operators, platform administrators, vulnerability management teams, and security teams who need to prioritize verifying exposure and assessing the security of their database connections.
Why it matters
CVE-2026-55860 is a vulnerability in MariaDB Connector/R2DBC that allows clear-text password authentication plugins to be used over unencrypted connections. Defenders should prioritize verifying exposure and assessing the security of their database connections.
- Verify exposure of MariaDB Connector/R2DBC versions prior to 1.4.1
- Assess the security of database connections
- Upgrade to version 1.4.1 or later
Technical summary
MariaDB Connector/R2DBC prior to 1.4.1 does not gate clear-text password authentication plugins on transport encryption. A hostile or man-in-the-middle MariaDB server can send an AuthSwitchRequest naming mysql_clear_password or dialog (PAM) over a plain-TCP unencrypted connection, and AuthenticationFlow permits ClearPasswordPluginFlow or PamPluginFlow to return the user's password as cleartext bytes on the wire.
Defensive priority
Defenders should prioritize verifying exposure of MariaDB Connector/R2DBC versions prior to 1.4.1 and assessing the security of their database connections.
Recommended defensive actions
- Verify exposure of MariaDB Connector/R2DBC versions prior to 1.4.1
- Assess the security of database connections
- Upgrade to version 1.4.1 or later
- Review compensating controls for exposed systems while remediation is scheduled and verified
- Check relevant monitoring, detection, and logs for exposed assets that need extra review
- Track exceptions, retest remediated assets, and close the item only after evidence is documented
- Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
Evidence notes
The CVE record and NVD detail page provide information on the vulnerability in MariaDB Connector/R2DBC. The issue is fixed in version 1.4.1. The vulnerability allows clear-text password authentication plugins to be used over unencrypted connections, which can lead to the disclosure of credentials. Defenders should verify exposure and assess the security of their database connections.
Sources and references
Verified primary and authoritative sources
-
CVE-2026-55860 CVE Program record
Publisher, destination, and source semantics verified
URL: https://www.cve.org/CVERecord?id=CVE-2026-55860
CVE Program - Official CVE Program record with source-provided CVE metadata.
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CVE-2026-55860 NVD vulnerability detail
Publisher, destination, and source semantics verified
URL: https://nvd.nist.gov/vuln/detail/CVE-2026-55860
NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.
Supplemental references
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Source reference
Unverified legacy reference
URL: https://github.com/mariadb-corporation/mariadb-connector-r2dbc/commit/be786603ec5530414996d2396157013e095b320a
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Source reference
Unverified legacy reference
URL: https://github.com/mariadb-corporation/mariadb-connector-r2dbc/releases/tag/1.4.1
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Source reference
Unverified legacy reference
URL: https://github.com/mariadb-corporation/mariadb-connector-r2dbc/security/advisories/GHSA-c857-9x2m-cvh2
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Source reference
Unverified legacy reference
URL: https://hackerone.com/reports/3784556
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Source reference
Unverified legacy reference
URL: https://jira.mariadb.org/browse/R2DBC-115
Methodology and review provenance
AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.