CVE-2026-71079: MySQL Connector/ODBC DOS Vulnerability

CVE-2026-71079 Overview

CVE-2026-71079 is a denial of service vulnerability in the Oracle MySQL Connectors product, specifically affecting the Connector/ODBC component. The flaw exists in version 26.7.0 and allows a low-privileged attacker with network access via multiple protocols to compromise the connector. Successful exploitation results in a hang or a frequently repeatable crash, producing a complete denial of service. The weakness is classified under [CWE-284] (Improper Access Control). Oracle addressed the issue in the Oracle Security Alert August 2026.

Critical Impact
Remote low-privileged attackers can trigger a complete denial of service against MySQL Connector/ODBC, disrupting database connectivity for applications that rely on the driver.

Affected Products

Oracle MySQL Connectors 26.7.0
MySQL Connector/ODBC component
Applications and services using the affected Connector/ODBC driver

Discovery Timeline

2026-08-18 - CVE-2026-71079 published to the National Vulnerability Database
2026-08-20 - Last updated in NVD database

Technical Details for CVE-2026-71079

Vulnerability Analysis

The vulnerability resides in Oracle MySQL Connector/ODBC version 26.7.0. It is described as easily exploitable, requiring only low privileges and network access. The impact is limited to availability, with no confidentiality or integrity effects. An attacker able to reach the connector over the network can send crafted input that causes the driver to hang or crash repeatedly. Because ODBC drivers typically run within the address space of the calling application, the resulting failure disrupts any service depending on database connectivity through the affected driver.

Root Cause

The issue is categorized as [CWE-284] Improper Access Control. Oracle's advisory notes that the flaw stems from insufficient enforcement within the Connector/ODBC component, allowing an authenticated but low-privileged actor to reach code paths that trigger the crash condition. Because attacks require only low privileges and no user interaction, the exposed surface can be reached from any account able to interact with the connector.

Attack Vector

Exploitation occurs over the network using multiple supported protocols against the Connector/ODBC endpoint. The scope is unchanged, meaning the impact is contained within the vulnerable component. Availability impact is high: the connector enters a hang state or crashes reliably. Applications relying on continuous database access experience outages until the connector process is restarted. The EPSS probability is 0.352 percent as of the scoring date, indicating limited observed exploitation activity, though the ease of exploitation warrants prompt remediation.

No verified public proof-of-concept code is available. See the Oracle Security Alert August 2026 for vendor technical details.

Detection Methods for CVE-2026-71079

Indicators of Compromise

Repeated crashes or hangs of processes linking against MySQL Connector/ODBC 26.7.0
Unexpected termination of applications immediately after establishing ODBC sessions to MySQL
Spikes in failed ODBC connection attempts followed by application restarts
Anomalous inbound network traffic to hosts exposing MySQL Connector/ODBC over supported protocols

Detection Strategies

Inventory endpoints and servers for MySQL Connector/ODBC version 26.7.0 using software asset management tools
Correlate application crash telemetry with concurrent ODBC network activity to identify triggered exploitation
Monitor Windows Event Log and Linux systemd journal entries for repeated faults in processes loading the ODBC driver DLL or shared object
Baseline normal ODBC connection volumes and alert on abnormal bursts of malformed requests

Monitoring Recommendations

Enable verbose logging on MySQL Connector/ODBC to capture crash-preceding statements and connection metadata
Ingest connector, application, and host telemetry into a centralized SIEM for correlation and retention
Track process availability metrics for services dependent on ODBC connectivity and alert on repeated restart cycles
Review authentication logs for low-privileged accounts making unusual connector interactions

How to Mitigate CVE-2026-71079

Immediate Actions Required

Identify all systems running MySQL Connector/ODBC 26.7.0 and prioritize them for patching
Apply the fixes documented in the Oracle Security Alert August 2026
Restrict network reachability of the Connector/ODBC endpoint to trusted hosts and management segments
Enforce least privilege on database accounts used by applications and services connecting through the driver

Patch Information

Oracle released remediation for CVE-2026-71079 as part of the Oracle Security Alert August 2026. Administrators should upgrade Connector/ODBC to the fixed release referenced in the advisory. Validate the update on non-production systems before broad rollout to confirm application compatibility with the patched driver.

Workarounds

Limit inbound network access to hosts running the affected connector using host and network firewalls
Remove or disable unused ODBC data source names (DSNs) referencing the vulnerable driver
Segment application tiers so that only trusted middleware can reach MySQL Connector/ODBC endpoints
Implement service watchdogs to automatically restart affected processes and reduce outage duration until patching completes

bash

# Example: identify installed Connector/ODBC version on Linux
odbcinst -q -d
odbcinst -j
# Example: restrict inbound access with iptables to trusted management CIDR
iptables -A INPUT -p tcp --dport 3306 -s 10.0.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 3306 -j DROP