CVE-2026-19854 Grafana CVE debrief

Who should care

Users of ClickHouse plugin with Native protocol and PDC or secure SOCKS configurations should review their setup for potential sensitive data exposure. This includes ClickHouse administrators, security teams, and operators who manage or interact with ClickHouse systems. Additionally, vulnerability management teams and security professionals responsible for monitoring and protecting sensitive data should be aware of this vulnerability and its potential impact.

Technical summary

The ClickHouse plugin uses Native protocol (the default) with PDC or secure SOCKS, but the connection library ignores TLS requests and communicates in the clear. This allows username, password, queries, and results to be read on the hop after the proxy. The server certificate is never checked, and a configured client certificate is not sent. This vulnerability could lead to sensitive data exposure, including authentication credentials and query results. Affected users should review their configurations and consider implementing compensating controls to protect sensitive data.

Defensive priority

Medium-priority defensive review recommended due to potential for sensitive data exposure in ClickHouse plugin communications.

Recommended defensive actions

• Review ClickHouse plugin configuration for Native protocol usage with PDC or secure SOCKS.
• Implement compensating controls to monitor and protect sensitive data in transit.
• Verify vendor remediation status and apply patches if available.
• Review system logs for signs of potential data exposure.
• Perform a thorough review of affected systems and networks.
• Consider implementing additional security measures such as encryption.
• Monitor for any updates or advisories from the vendor regarding this vulnerability.

Evidence notes

Evidence from official CVE and NVD sources indicates potential for sensitive data exposure in ClickHouse plugin communications. Limited details on vendor remediation or affected scope. The ClickHouse plugin's use of Native protocol with PDC or secure SOCKS configurations may expose sensitive information, including usernames, passwords, queries, and results, on the hop after the proxy due to the connection library ignoring TLS requests. Server certificate verification is not performed, and configured client certificates are not sent. Users should verify their configurations and monitor for potential exposures. Additional review of plugin configurations and compensating controls is recommended.

Sources and references

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.