CVE-2026-89039Network attack vectorHinoki check available

Arbitrary file read via unchecked prompt path

Published Oct 5, 2026 · Updated Oct 5, 2026

Arbitrary file read in Grafana Labs mcp-k6 0.3.0 and later allows attackers to retrieve server-readable files via a prompt argument. The convert_playwright_script prompt treats a bare playwright_script value as a path and reads it without the working-directory check applied to @-prefixed paths; symlinks also bypass that check. An attacker must be able to invoke the prompt; HTTP mode has no built-in authentication, and disclosure is limited to files readable by the server process.

CVSS severityUnavailable
Unscored
EPSS probability0.38%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Arbitrary file read in Grafana Labs mcp-k6 0.3.0 and later allows attackers to retrieve server-readable files via a prompt argument. The convert_playwright_script prompt treats a bare playwright_script value as a path and reads it without the working-directory check applied to @-prefixed paths; symlinks also bypass that check. An attacker must be able to invoke the prompt; HTTP mode has no built-in authentication, and disclosure is limited to files readable by the server process.

The record

CVE
CVE-2026-89039
Published
Oct 5, 2026
Updated
Oct 5, 2026
Vendor
Grafana Labs
Product
mcp-k6
Classifications
T1005
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 5, 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=0.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Grafana Labs · mcp-k6version=0.3.0

Published CVSS scores

No CVSS assessment is available in this record.

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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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