CVE-2026-19854

Credential and query disclosure via dropped TLS

Published Aug 27, 2026 · Updated Aug 27, 2026

Cleartext transmission in Grafana Labs ClickHouse data source 3.1.0 through 4.20.0 allows man-in-the-middle attackers to read database traffic. When Native protocol is used through PDC or secure SOCKS, the connection library ignores the plugin's TLS request, sends traffic in cleartext, skips server-certificate validation, and omits a configured client certificate. The attacker must observe the hop after the proxy; exposed data is limited to ClickHouse usernames, passwords, queries, and results.

CVSS severity6.1
Medium
EPSS probability0.05%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cleartext transmission in Grafana Labs ClickHouse data source 3.1.0 through 4.20.0 allows man-in-the-middle attackers to read database traffic. When Native protocol is used through PDC or secure SOCKS, the connection library ignores the plugin's TLS request, sends traffic in cleartext, skips server-certificate validation, and omits a configured client certificate. The attacker must observe the hop after the proxy; exposed data is limited to ClickHouse usernames, passwords, queries, and results.

The record

CVE
CVE-2026-19854
Published
Aug 27, 2026
Updated
Aug 27, 2026
Vendor
Grafana Labs
Product
Grafana ClickHouse data source
Classifications
CWE-319, T1040
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.1.0 <=4.20.0

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Grafana Labs · Grafana ClickHouse data sourceversion=3.1.0 <=4.20.0

Published CVSS scores

6.1Grafana LabsCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-319Cleartext Transmission of Sensitive Information
T1040Network Sniffing

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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