Is the campaign still active?

No. Active tracking ended Oct 30, 2026; this page remains as a labeled historical research record and does not imply the threat is currently active.

What evidence supports this record?

The record cites 7 primary sources, names 2 reviewed artifacts, and was last fully reviewed Oct 30, 2026 by HOL Guard Security Publishing. Its uncertainty and limitations are stated on the record itself.

How can this record be cited or exported?

The permalink above is permanent. The full record can be downloaded from this page as JSON, an artifact CSV, and a STIX 2.1 bundle, and corrections can be requested through the published correction path on the record. The vendor description is one sentence. ClickHouse has not said which interface or settings are involved, and the CVSS vector rates attack complexity High.

critical severityConfidence mediumHistorical record

ClickHouse Server unauthenticated RCE (CVE-2026-116366): self-hosted servers reachable on the network can be taken over without a password

Direct answer

ClickHouse Server unauthenticated RCE (CVE-2026-116366): self-hosted servers reachable on the network can be taken over without a password, also tracked as CVE-2026-116366 / ClickHouse unauthenticated RCE / ClickHouse Server integer overflow RCE is a critical-severity threat campaign HOL Guard tracked from Oct 30, 2026 to Oct 30, 2026, verified against 7 primary sources and last reviewed Oct 30, 2026. Active tracking has ended and the record remains published as a permanent historical research record.

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.

Also tracked as CVE-2026-116366 · ClickHouse unauthenticated RCE · ClickHouse Server integer overflow RCE · ClickHouse 26.8.36.3 security fix

First observed: Oct 30, 2026
Last observed: Oct 30, 2026
Last reviewed: Oct 30, 2026
Tracking ended: Oct 30, 2026

Record exports

JSON record Artifact CSV STIX 2.1 bundle

Uncertainty and limitations

Read the evidence limits before acting on this record.

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.

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.

Guard coverage and policy

What Guard's reviewed assertions do and do not claim for this campaign, and the reviewed starting points for defense.

Not covered, or partially covered

not covered
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.

No campaign-specific policy guidance is published.

Safe next step. Campaign guidance is defensive context. It does not auto-apply policy or claim universal campaign coverage.

Open policy controls Campaign-specific emergency policy starting point

Timeline

Reviewed events, oldest first, each tied to a verified source.

Oct 26, 2026Vendor action
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.
Source:Docker Hub clickhouse/clickhouse-server tags
Oct 30, 2026Disclosure
ClickHouse publishes CVE-2026-116366 in its security changelog and CVE record with fixed versions and states Cloud and BYOC are patched.
Sources:ClickHouse security changelog: CVE-2026-116366·CVE-2026-116366 CVE record (ClickHouse CNA)
Oct 30, 2026Update
HOL Guard publishes an operator write-up with version checks, upgrade commands, exposure checks and Langfuse/SigNoz bundled-image notes.
Source:HOL: ClickHouse CVE-2026-116366 unauthenticated RCE, what to upgrade

Publication clock: 1.0 hours from reviewed disclosure timestamp to HOL publication; 12-hour critical target; within target.

Reviewed artifacts

The specific artifacts this record concerns, as reviewed. Names and versions are shown as text; a registry link is not recorded here.

ClickHouse Server@26.3 <26.3.62.3, 26.8 <26.8.36.3, 26.9 <26.9.27.3, 26.10 <26.10.3.7genericpackage
clickhouse/clickhouse-server@fixed tags 26.3.62.3, 26.8.36.3, 26.9.27.3, 26.10.3.7dockerpackage

Sources

Every claim on this record is traceable to the sources below.

Campaign questions, answered

Reviewed in full by HOL Guard Security Publishing.

Published: October 30, 2026
Last full review: October 30, 2026
Last modified: October 30, 2026

Report a correction

Record HGTC-2026-8078E28C