{ "schemaVersion": "guard-threat-campaign/v1", "id": "HGTC-2026-8078E28C", "slug": "cve-2026-116366-clickhouse-unauthenticated-rce-upgrade", "title": "ClickHouse Server unauthenticated RCE (CVE-2026-116366): self-hosted servers reachable on the network can be taken over without a password", "aliases": [ "CVE-2026-116366", "ClickHouse unauthenticated RCE", "ClickHouse Server integer overflow RCE", "ClickHouse 26.8.36.3 security fix" ], "summary": "On 2026-10-30 ClickHouse disclosed CVE-2026-116366: under certain conditions, an unauthenticated user with network access can execute arbitrary code on ClickHouse Server. The ClickHouse CNA rates it CVSS 4.0 9.5 (AV:N/AC:H/PR:N/UI:N), classifies it as CWE-190 integer overflow, and credits Elshad Toklayev. Fixed open-source builds are 26.3.62.3-lts, 26.8.36.3-lts, 26.9.27.3-stable and 26.10.3.7-stable. ClickHouse says the fix is applied to all ClickHouse Cloud and BYOC deployments. ClickHouse has not named the affected interface, the conditions, or published a proof of concept. Unsupported trains (26.7, 26.4 to 26.6, 26.1, 26.2, 25.x and older) receive no fix. Langfuse and SigNoz self-host defaults bundle ClickHouse 25.12 and 25.5.6 images, which are off support.", "status": "published", "severity": "critical", "confidence": "medium", "uncertainty": "The vendor description is one sentence. ClickHouse has not said which interface or settings are involved, and the CVSS vector rates attack complexity High. The CVE record lists only the four supported trains with defaultStatus affected; whether unsupported trains such as 25.x carry the bug is not stated. No exploitation or public exploit code has been reported; not in CISA KEV as of the 2026-10-29 catalog.", "firstObservedAt": "2026-10-30T10:59:00Z", "lastObservedAt": "2026-10-30T11:51:55Z", "publishedAt": "2026-10-30T11:59:06.793Z", "reviewedAt": "2026-10-30T11:58:59.578Z", "expiresAt": "2026-10-30T11:51:55Z", "reviewer": "HOL Guard Security Publishing", "sources": [ { "id": "clickhouse-security-changelog", "label": "ClickHouse security changelog: CVE-2026-116366", "url": "https://clickhouse.com/docs/resources/changelogs/security-changelog", "sourceType": "vendor_advisory", "observedAt": "2026-10-30T10:59:00Z" }, { "id": "cve-record", "label": "CVE-2026-116366 CVE record (ClickHouse CNA)", "url": "https://www.cve.org/CVERecord?id=CVE-2026-116366", "sourceType": "vulnerability_database", "observedAt": "2026-10-30T11:00:11Z" }, { "id": "clickhouse-security-md", "label": "ClickHouse SECURITY.md supported versions", "url": "https://github.com/ClickHouse/ClickHouse/blob/master/SECURITY.md", "sourceType": "maintainer_advisory", "observedAt": "2026-10-30T00:00:00Z" }, { "id": "dockerhub-tags", "label": "Docker Hub clickhouse/clickhouse-server tags", "url": "https://hub.docker.com/r/clickhouse/clickhouse-server/tags", "sourceType": "other_primary", "observedAt": "2026-10-26T18:20:57Z" }, { "id": "langfuse-compose", "label": "Langfuse docker-compose.yml (ClickHouse 25.12 image)", "url": "https://github.com/langfuse/langfuse/blob/main/docker-compose.yml", "sourceType": "other_primary", "observedAt": "2026-10-30T00:00:00Z" }, { "id": "signoz-docker", "label": "SigNoz Docker install docs (ClickHouse 25.5.6 image)", "url": "https://signoz.io/docs/install/docker/", "sourceType": "other_primary", "observedAt": "2026-10-30T00:00:00Z" }, { "id": "hol-blog", "label": "HOL: ClickHouse CVE-2026-116366 unauthenticated RCE, what to upgrade", "url": "https://hol.org/blog/cve-2026-116366-clickhouse-unauthenticated-rce-upgrade", "sourceType": "other_primary", "observedAt": "2026-10-30T11:51:55Z" } ], "artifacts": [ { "id": "clickhouse-server", "artifactClass": "package", "ecosystem": "generic", "name": "ClickHouse Server", "version": "26.3 <26.3.62.3, 26.8 <26.8.36.3, 26.9 <26.9.27.3, 26.10 <26.10.3.7", "defanged": false }, { "id": "clickhouse-docker", "artifactClass": "package", "ecosystem": "docker", "name": "clickhouse/clickhouse-server", "version": "fixed tags 26.3.62.3, 26.8.36.3, 26.9.27.3, 26.10.3.7", "defanged": false } ], "indicators": [], "timeline": [ { "id": "fixed-images-pushed", "occurredAt": "2026-10-26T00:08:20Z", "eventType": "vendor_action", "summary": "Docker Hub shows clickhouse/clickhouse-server 26.10.3.7 (and latest, 26.10) pushed; 26.3.62.3, 26.9.27.3 and 26.8.36.3 follow on 2026-10-26.", "sourceIds": [ "dockerhub-tags" ] }, { "id": "clickhouse-advisory", "occurredAt": "2026-10-30T10:59:00Z", "eventType": "disclosure", "summary": "ClickHouse publishes CVE-2026-116366 in its security changelog and CVE record with fixed versions and states Cloud and BYOC are patched.", "sourceIds": [ "clickhouse-security-changelog", "cve-record" ] }, { "id": "hol-blog-published", "occurredAt": "2026-10-30T11:51:55Z", "eventType": "other", "summary": "HOL Guard publishes an operator write-up with version checks, upgrade commands, exposure checks and Langfuse/SigNoz bundled-image notes.", "sourceIds": [ "hol-blog" ] } ], "coverage": [ { "assertionId": "guard-not-clickhouse-server", "relationship": "not_covered", "limitation": "HOL Guard reviews AI coding agent actions on developer machines. It does not patch or inspect ClickHouse servers; the fix is upgrading ClickHouse and restricting network access." } ], "policies": [], "limitations": [ "ClickHouse Cloud and BYOC deployments are patched by ClickHouse, per the security changelog.", "Servers bound only to localhost or a private Docker network are not reachable by internet attackers, though other local processes and containers can still reach them.", "No public exploit, no in-the-wild exploitation report and no CISA KEV listing as of 2026-10-30.", "ClickHouse has not named the vulnerable interface, so all listeners should be treated as in scope." ], "correctionHref": "/guard/security/campaigns/cve-2026-116366-clickhouse-unauthenticated-rce-upgrade/corrections" }