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NifiApplication · Apache

CVE-2026-39816

HIGH · 8.8 CVSS v3.1 Published 2026-05-08
Fix available
A fix is available. Upgrade to 2.9.0 or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click

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
The optional extension component TinkerpopClientService is missing the Restricted annotation with the Execute Code Required Permission in Apache NiFi 2.0.0-M1 through 2.8.0. The TinkerpopClientService supports configuration of ByteCode Submission for the Script Submission Type, enabling Groovy Script execution in the service prior to submitting the query. The missing Restricted annotation allows users without the Execute Code Permission to configure the Service in installations that use fine-grained authorization and have the optional TinkerpopClientService installed. Apache NiFi installations that do not have the nifi-other-graph-services-nar installed are not subject to this vulnerability. Upgrading to Apache NiFi 2.9.0 is the recommended mitigation.

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

The optional TinkerpopClientService in Apache NiFi 2.0.0-M1 through 2.8.0 is missing the Restricted annotation that enforces Execute Code Permission. This allows users with fine-grained authorization but without Execute Code Permission to configure the service to execute arbitrary Groovy scripts, resulting in code execution capability.

MitigationUpgrade to Apache NiFi 2.9.0, or verify that the nifi-other-graph-services-nar is not installed in environments where this extension is not required.

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

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
NifiApplication
Affected:>= 2.0.0, < 2.9.0

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

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 Apache NiFi version
    Check the nifi-api JAR file in the lib directory, or inspect the startup logs for the NiFi version number. Typical path: /lib/nifi-api-[version].jar or look for 'NiFi Version' in logs/nifi-app.log
    Affected if The version is >= 2.0.0 and < 2.9.0
  2. Locate the graph services NAR
    Search for the file nifi-other-graph-services-nar in the lib directory or nar directory. This NAR contains the vulnerable TinkerpopClientService. Command: find /path/to/nifi -name 'nifi-other-graph-services-nar*'
    Affected if The nifi-other-graph-services-nar file is present in the NiFi deployment
  3. Verify TinkerpopClientService is available
    In the NiFi UI, go to Controller Settings > Services and search for 'TinkerPop Client Service', or check the nar's bundle.xml for the TinkerpopClientService class definition
    Affected if The TinkerpopClientService is listed and can be configured by users

A user is affected if their NiFi version is between 2.0.0 and 2.8.0 (inclusive) AND the nifi-other-graph-services-nar containing TinkerpopClientService is installed.

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
Upgrade available Upgrade to 2.9.0 or later
Fixed in 2.9.0
Interim mitigation

Upgrade to Apache NiFi 2.9.0, or verify that the nifi-other-graph-services-nar is not installed in environments where this extension is not required.

Recommended fix High confidence

Apache NiFi 2.9.0

  1. 1. Plan and schedule a maintenance window for the Apache NiFi upgrade
  2. 2. Back up the current NiFi configuration, flow.xml.gz, and any custom NAR files
  3. 3. Stop the Apache NiFi service
  4. 4. Upgrade to Apache NiFi 2.9.0 by installing the new version binaries
  5. 5. Ensure the nifi-other-graph-services-nar is also upgraded to the 2.9.0 version
  6. 6. Start the Apache NiFi service
  7. 7. Verify the TinkerpopClientService now requires Execute Code Permission for configuration

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

Fix this in Nifi Scoped from the published advisory
  • Consultation3.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
17.0 hours of engineering $3,000
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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-2026-39816 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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