CVE-2026-39816Public exploitNetwork attack vector

Authenticated code execution via missing service restriction

Published May 8, 2026 · Updated May 8, 2026

Missing authorization in Apache NiFi 2.0.0-M1 through 2.8.0 allows remote authenticated users to execute Groovy code in the NiFi JVM. TinkerpopClientService accepts ByteCode Submission queries and runs them as Groovy because its class lacks the Restricted annotation that enforces the Execute Code permission. Exploitation requires fine-grained authorization, the optional nifi-other-graph-services-nar bundle, and flow-design privileges; code runs as the NiFi service account.

CVSS severity8.8
High
EPSS probability0.76%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authorization in Apache NiFi 2.0.0-M1 through 2.8.0 allows remote authenticated users to execute Groovy code in the NiFi JVM. TinkerpopClientService accepts ByteCode Submission queries and runs them as Groovy because its class lacks the Restricted annotation that enforces the Execute Code permission. Exploitation requires fine-grained authorization, the optional nifi-other-graph-services-nar bundle, and flow-design privileges; code runs as the NiFi service account.

The record

CVE
CVE-2026-39816
Published
May 8, 2026
Updated
May 8, 2026
Vendor
The Apache Software Foundation
Product
Apache NiFi
Classifications
CWE-862, T1059
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 8, 2026CVE publishedPublication date reported by the CVE source.
  2. May 8, 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=2.0.0-M1 <=2.8.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Apache Software Foundation · Apache NiFiversion=2.0.0-M1 <=2.8.0

Published CVSS scores

8.8GitLab Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-862Missing Authorization
T1059Command and Scripting Interpreter

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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