dbcve.org
Improper Access ControlWeakness · CWE-284

CVE-2026-40452

HIGH · 7.5 CVSS v3.1 Published 2026-07-10
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click 6 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Incorrect Authorization, Improper Access Control vulnerability in Apache IoTDB. Authorization bypass in /rest/v2/fastLastQuery exposes last-value data to unauthorized authenticated users. This issue affects Apache IoTDB: from 1.3.5 before 1.3.8, from 2.0.5 before 2.0.10. Users are recommended to upgrade to version 2.0.10, which fixes the issue.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

This is an authorization bypass vulnerability in Apache IoTDB's REST API endpoint /rest/v2/fastLastQuery. The improper access control allows authenticated users to retrieve last-value data from time series they are not authorized to access, exposing sensitive data to unauthorized authenticated users.

MitigationUpgrade Apache IoTDB to version 2.0.10 (or 1.3.8 for the 1.x branch) which contains the proper authorization fix for the /rest/v2/fastLastQuery endpoint.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify IoTDB installation and version
    Check for IoTDB installation directory or running process. Common paths include /opt/iotdb, /usr/local/iotdb, or check running Java processes with: ps aux | grep iotdb. Look for version in conf/iotdb-common.properties or startup logs.
    Affected if The installed version is below 1.3.8 (1.x branch) or below 2.0.10 (2.x branch)
  2. Verify REST API service is enabled
    Check iotdb-config.properties or iotdb-common.properties for property 'iotdb.rpc.enable' set to true, or confirm port 6667 (default REST API) is listening with: netstat -tlnp | grep 6667 or ss -tlnp | grep 6667.
    Affected if REST API is enabled and port 6667 is open
  3. Confirm authorization is configured
    Check if authentication is enabled in conf/iotdb-common.properties: look for 'iotdb.auth.enforce=true' or similar authorization enforcement settings. Also verify users have been configured.
    Affected if Authorization is configured but the /rest/v2/fastLastQuery endpoint bypasses it
  4. Check endpoint exposure
    Inspect REST module configuration in conf/iotdb-rest.properties or equivalent. Verify the /rest/v2/fastLastQuery endpoint is available. Test with curl: curl -u <user> http://localhost:6667/rest/v2/fastLastQuery -X POST -d '{"paths":["/unauthorized/series"]}'
    Affected if The endpoint responds and returns data without proper authorization checks for the requested series

A user is affected if they run Apache IoTDB versions prior to 1.3.8 or 2.0.10, have the REST API enabled, and the /rest/v2/fastLastQuery endpoint is accessible to authenticated users who should not have access to certain time series data.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Apache IoTDB to version 2.0.10 (or 1.3.8 for the 1.x branch) which contains the proper authorization fix for the /rest/v2/fastLastQuery endpoint.

Recommended fix High confidence

2.0.10 (or 1.3.8 for 1.x branch)

  1. Download Apache IoTDB version 2.0.10 (or 1.3.8 for the 1.x branch) from the official Apache IoTDB distribution repository
  2. Stop the currently running IoTDB instance
  3. Backup the existing IoTDB installation directory and any important data
  4. Extract the new version to replace the existing installation
  5. Migrate any necessary configuration files from the old version to the new version if required
  6. Start the IoTDB service with the new version
  7. Verify the /rest/v2/fastLastQuery endpoint now properly enforces authorization

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation4.0 h
  • Testing8.0 h
  • Review / QA4.0 h
20.0 hours of engineering $3,440
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-40452 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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