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Full vulnerability report · 2026
CVE-2026-55858High confidence

MariaDB Connector/J: Inappropriate Encoding for Output Context in org.mariadb.jdbc:mariadb-java-client

mariadb-corporation · mariadb-connector-j

Official source article: GitHub GHSA-XVR9-35CR-46V9 ↗. Check the applicable product and release in the original source.

5.9MediumCVSS 3.1
Recommended action
Patch only the product branches with a verified fix

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 44 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 0.87% for the current model date.

Compensating controls

  • Apply the linked authoritative mitigation while planning the permanent fix.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs mariadb-corporation mariadb-connector-j and falls inside the recorded affected range.
  2. Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: As exposure requiresRemediation target: Within 365 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Cross-source reconciliation

Remediation availability differs by product scope

Verified remediation exists for at least one product or source, but 44 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Open-source package ranges8 source-attributed ranges

These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.

Ecosystem and packageAffected rangeFirst fixed versionEvidence
Mavenorg.mariadb.jdbc:mariadb-java-clientECOSYSTEM: introduced 0; fixed 2.7.142.7.14OSV record ↗aggregator derived · 10 Sep 2026
Mavenorg.mariadb.jdbc:mariadb-java-clientECOSYSTEM: introduced 3.0.0; fixed 3.3.53.3.5OSV record ↗aggregator derived · 10 Sep 2026
Mavenorg.mariadb.jdbc:mariadb-java-clientECOSYSTEM: introduced 3.4.0; fixed 3.4.33.4.3OSV record ↗aggregator derived · 10 Sep 2026
Mavenorg.mariadb.jdbc:mariadb-java-clientECOSYSTEM: introduced 3.5.0; fixed 3.5.93.5.9OSV record ↗aggregator derived · 10 Sep 2026
mavenorg.mariadb.jdbc:mariadb-java-client< 2.7.142.7.14GitHub advisory ↗upstream repository advisory · 28 Aug 2026
mavenorg.mariadb.jdbc:mariadb-java-client>= 3.0.0, < 3.3.53.3.5GitHub advisory ↗upstream repository advisory · 28 Aug 2026
mavenorg.mariadb.jdbc:mariadb-java-client>= 3.4.0, < 3.4.33.4.3GitHub advisory ↗upstream repository advisory · 28 Aug 2026
mavenorg.mariadb.jdbc:mariadb-java-client>= 3.5.0, < 3.5.93.5.9GitHub advisory ↗upstream repository advisory · 28 Aug 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2026-55858 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityorg.mariadb.jdbc/mariadb-java-client: MariaDB Connector/J: Silent data corruption due to character set mismatch
44 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • openshift-pipelines/pipelines-console-plugin-pf5-rhel9 as a component of OpenShift Pipelines
  • openshift-pipelines/pipelines-console-plugin-rhel8 as a component of OpenShift Pipelines
  • openshift-pipelines/pipelines-console-plugin-rhel9 as a component of OpenShift Pipelines
  • openshift-pipelines/pipelines-hub-ui-rhel8 as a component of OpenShift Pipelines
  • openshift-pipelines/pipelines-hub-ui-rhel9 as a component of OpenShift Pipelines
  • mariadb-java-client as a component of Red Hat build of Debezium 3
  • keycloak/rhbk-openshift-rhel9 as a component of Red Hat Build of Keycloak
  • mariadb-java-client as a component of Red Hat Build of Keycloak
  • rhbk/keycloak-rhel9 as a component of Red Hat Build of Keycloak
  • mariadb-java-client as a component of Red Hat build of Quarkus
  • mariadb-java-client.src as a component of Red Hat Enterprise Linux 10
  • Judy.src (mariadb:10.3) as a component of Red Hat Enterprise Linux 8
Summary
A flaw was found in MariaDB Connector/J, a component used to connect Java applications to MariaDB and MySQL databases. The connector incorrectly assumes a UTF-8 character set for communication, even if the database server changes its client character set to a non-UTF-8 value during a session. This mismatch can lead to silent data corruption, where data is written and read incorrectly, and may also allow attackers to bypass security mechanisms like byte-wise quoting or escaping.
Remediation
Upgrade MariaDB Connector/J to a fixed version (2.7.14, 3.3.5, 3.4.3, or 3.5.9, as appropriate for the branch in use), which rejects any post-initialization character set other than utf8, utf8mb3, or utf8mb4 and closes the connection. Where upgrading is not immediately possible, avoid changing character_set_client after connection establishment and connect only to trusted database servers.
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-68021

No EUVD known-exploited evidence

MariaDB Connector/J is used to connect applications developed in Java to MariaDB and MySQL databases. Prior to 2.7.14, 3.3.5, 3.4.3, and 3.5.9, the connector encodes and decodes protocol text and performs client-side escaping under the assumption that the connection character set is UTF-8. The server can report a mid-session change to character_set_client through OK-packet session-state tracking, including a change caused by SET NAMES, a stored routine or trigger, server configuration, or a hostile server. If character_set_client changes to a non-UTF-8 value, the driver continues to read and write UTF-8 while the server interprets the same bytes under another 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 causes SQLException with SQLState 08000 and closes the connection. This issue is fixed in versions 2.7.14, 3.3.5, 3.4.3, and 3.5.9.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
5.9 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionPatch only the product branches with a verified fix

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 44 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
01

What, why and how

MariaDB Connector/J is used to connect applications developed in Java to MariaDB and MySQL databases. Prior to 2.7.14, 3.3.5, 3.4.3, and 3.5.9, the connector encodes and decodes protocol text and performs client-side escaping under the assumption that the connection character set is UTF-8. The server can report a mid-session change to character_set_client through OK-packet session-state tracking, including a change caused by SET NAMES, a stored routine or trigger, server configuration, or a hostile server. If character_set_client changes to a non-UTF-8 value, the driver continues to read and write UTF-8 while the server interprets the same bytes under another 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 causes SQLException with SQLState 08000 and closes the connection. This issue is fixed in versions 2.7.14, 3.3.5, 3.4.3, and 3.5.9.

What

MariaDB Connector/J is used to connect applications developed in Java to MariaDB and MySQL databases. Prior to 2.7.14, 3.3.5, 3.4.3, and 3.5.9, the connector encodes and decodes protocol text and performs client-side escaping under the assumption that the connection character set is UTF-8. The server can report a mid-session change to character_set_client through OK-packet session-state tracking, including a change caused by SET NAMES, a stored routine or trigger, server configuration, or a hostile server. If character_set_client changes to a non-UTF-8 value, the driver continues to read and write UTF-8 while the server interprets the same bytes under another 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 causes SQLException with SQLState 08000 and closes the connection. This issue is fixed in versions 2.7.14, 3.3.5, 3.4.3, and 3.5.9.

Why

The product uses or specifies an encoding when generating output to a downstream component, but the specified encoding is not the same as the encoding that is expected by the downstream component.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

MariaDB Connector/J is used to connect applications developed in Java to MariaDB and MySQL databases. Prior to 2.7.14, 3.3.5, 3.4.3, and 3.5.9, the connector encodes and decodes protocol text and performs client-side escaping under the assumption that the connection character set is UTF-8. The server can report a mid-session change to character_set_client through OK-packet session-state tracking, including a change caused by SET NAMES, a stored routine or trigger, server configuration, or a hostile server. If character_set_client changes to a non-UTF-8 value, the driver continues to read and write UTF-8 while the server interprets the same bytes under another 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 causes SQLException with SQLState 08000 and closes the connection. This issue is fixed in versions 2.7.14, 3.3.5, 3.4.3, and 3.5.9.

Why

The product uses or specifies an encoding when generating output to a downstream component, but the specified encoding is not the same as the encoding that is expected by the downstream component.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Inappropriate Encoding for Output Context → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-838 ↗

CWE-838: Inappropriate Encoding for Output Context. The product uses or specifies an encoding when generating output to a downstream component, but the specified encoding is not the same as the encoding that is expected by the downstream component.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.IHighIntegrity impact: A successful attack can cause a major loss.ANoneAvailability impact: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-838
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-68021Official EUVD mapping

MariaDB Connector/J is used to connect applications developed in Java to MariaDB and MySQL databases. Prior to 2.7.14, 3.3.5, 3.4.3, and 3.5.9, the connector encodes and decodes protocol text and performs client-side escaping under the assumption that the connection character set is UTF-8. The server can report a mid-session change to character_set_client through OK-packet session-state tracking, including a change caused by SET NAMES, a stored routine or trigger, server configuration, or a hostile server. If character_set_client changes to a non-UTF-8 value, the driver continues to read and write UTF-8 while the server interprets the same bytes under another 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 causes SQLException with SQLState 08000 and closes the connection. This issue is fixed in versions 2.7.14, 3.3.5, 3.4.3, and 3.5.9.

Official EUVD record ↗
BSI · German · WID-SEC-2026-3089MariaDB Connectors: Mehrere Schwachstellen

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in MariaDB Connectors ausnutzen, um SQL-Injection-Angriffe durchzuführen, Sicherheitsmaßnahmen zu umgehen und Daten offenzulegen oder zu manipulieren.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260902Security Bulletin 2 Sept 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 2 Sept 2026, published on 2 September 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix availability varies by product
Affected
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
Workaround
Upgrade MariaDB Connector/J to a fixed version (2.7.14, 3.3.5, 3.4.3, or 3.5.9, as appropriate for the branch in use), which rejects any post-initialization character set other than utf8, utf8mb3, or utf8mb4 and closes the connection. Where upgrading is not immediately possible, avoid changing character_set_client after connection establishment and connect only to trusted database servers.
04

Evidence and provenance

Published 28 Aug 2026 · Last source change 1 Sept 2026, 02:06 UTC · CWE-838 · Inappropriate Encoding for Output Context

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-29
European sourceENISA EUVD · EUVD-2026-68021
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD awaiting enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. ENISA EUVD mappingEUVD-2026-68021 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2026-68021"}
    ENISA EUVD ↗
  2. Affected versionsThe structured affected or fixed version information changed.
    Before
    < 2.7.14; >= 3.0.0-alpha, < 3.3.5; >= 3.4.0, < 3.4.3; >= 3.5.0, < 3.5.9 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    mariadb-connector-j: < 2.7.14, >= 3.0.0-alpha, < 3.3.5, >= 3.4.0, < 3.4.3, >= 3.5.0, < 3.5.9 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    CNA ↗
  3. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2026-68021↗Vendor CSAF · Red Hat Product Security↗CVE authority or vendor reference · GitHub GHSA-XVR9-35CR-46V9↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-55858 · cve.blacktree.nl