ClickHouse 26.10.3.7 Fixes Unauthenticated Server RCE
Tech GuruQuick Answer
ClickHouse CVE-2026-116366 can permit unauthenticated remote code execution under certain conditions. Inventory exposed servers, move each maintained branch to the listed fixed build, confirm managed Cloud or BYOC status, validate clusters and clients, review exposed systems where warranted, and retain evidence.
Confirm Scope And Apply The Supported Remediation
What to do now: Inventory ClickHouse clusters, exact builds and support streams, listening interfaces, authentication and network exposure, replicas, clients, owners, backups, and maintenance windows. Match each server to ClickHouse's exact fixed branch and deployment model; do not infer that service reachability proves exploitation or that a managed-service fix covers self-managed nodes. Upgrade self-managed nodes to 26.3.62.3-lts, 26.8.36.3-lts, 26.9.27.3-stable, or 26.10.3.7-stable as applicable and restrict untrusted network access during rollout. Confirm running builds on every replica, test queries, ingestion, replication and recovery, review process and network evidence on exposed systems where warranted, and retain deployment records.
Last verified: 2026-10-30 UTC. Recheck the authoritative advisory and supported distribution channel before changing production.
Scope And Authority
| Product scope | ClickHouse Server open-source, Cloud, and BYOC deployments |
|---|---|
| Advisory | CVE-2026-116366 |
| CVE | CVE-2026-116366 |
| Authoritative release date | 2026-10-30 10:44:42 UTC |
| Authority revision date | 2026-10-30 10:47:47 UTC |
| Affected versions | Affected ClickHouse Server releases before the fixed 26.3.62.3-lts, 26.8.36.3-lts, 26.9.27.3-stable, and 26.10.3.7-stable builds under the conditions described by ClickHouse. |
| Fixed version | ClickHouse 26.3.62.3-lts, 26.8.36.3-lts, 26.9.27.3-stable, or 26.10.3.7-stable; ClickHouse states Cloud and BYOC were fixed by the service |
| CVSS base score | 9.5 (CVSS v4.0) |
| CVSS severity | Critical |
| Exploitation status | ClickHouse does not state that this vulnerability is being maliciously exploited.; no exploitation claim is inferred. |
What Changed
ClickHouse says an unauthenticated network attacker could execute code on ClickHouse Server under certain conditions; fixed open-source builds and managed-service remediation are available.
What To Validate Now
- Inventory. Inventory ClickHouse clusters, exact builds and support streams, listening interfaces, authentication and network exposure, replicas, clients, owners, backups, and maintenance windows.
- Establish applicability. Match each server to ClickHouse's exact fixed branch and deployment model; do not infer that service reachability proves exploitation or that a managed-service fix covers self-managed nodes.
- Remediate. Upgrade self-managed nodes to 26.3.62.3-lts, 26.8.36.3-lts, 26.9.27.3-stable, or 26.10.3.7-stable as applicable and restrict untrusted network access during rollout.
- Validate. Confirm running builds on every replica, test queries, ingestion, replication and recovery, review process and network evidence on exposed systems where warranted, and retain deployment records.
- Retain evidence. Preserve asset and owner identifiers, the applicability decision, before-and-after versions, change approval, installation output, validation results, and any exception or rollback record.
Operational Cautions
Coordinate rolling upgrades and quorum-sensitive operations. Preserve evidence before rebuilding a suspected host and do not substitute a build from another release stream without support confirmation.
Evidence To Retain
- Exact product, release stream, package or application version, enabled feature, environment, and accountable owner.
- UTC timestamps, authority revision, approved change record, installer or package-manager output, and resulting version.
- Relevant logs and monitoring evidence, test results, exceptions, compensating controls, and rollback decisions.
Related TechGeeks Resources
Authoritative References
Correction policy: If the authority changes affected versions, fixed versions, severity, exploitation information, mitigations, or required action, TechGeeks will update this notice and its verification date.
