Summary
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.
Impact
The application does not perform an authorization check before performing a sensitive operation. Typical impact: unauthorized access to restricted functionality or data.
CVE-2026-39816 has a CVSS score of 8.8 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.9.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-39816? CVE-2026-39816 is a high-severity missing authorization vulnerability in org.apache.nifi:nifi-other-graph-services-nar (maven), affecting versions >= 2.0.0-M1, <= 2.8.0. It is fixed in 2.9.0. The application does not perform an authorization check before performing a sensitive operation.
- How severe is CVE-2026-39816? CVE-2026-39816 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of org.apache.nifi:nifi-other-graph-services-nar are affected by CVE-2026-39816? org.apache.nifi:nifi-other-graph-services-nar (maven) versions >= 2.0.0-M1, <= 2.8.0 is affected.
- Is there a fix for CVE-2026-39816? Yes. CVE-2026-39816 is fixed in 2.9.0. Upgrade to this version or later.
- Is CVE-2026-39816 exploitable, and should I be worried? Whether CVE-2026-39816 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-39816 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-39816? Upgrade
org.apache.nifi:nifi-other-graph-services-narto 2.9.0 or later.