Is CVE-2026-39816 actively exploited?

No active exploitation of CVE-2026-39816 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-39816 be exploited remotely?

Yes. CVE-2026-39816 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-39816?

CVE-2026-39816 has a CVSS score of 8.8 (HIGH).

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HIGH

CVE-2026-39816

CWE-862Published: May 8, 2026· Updated: May 9, 2026

8.8

CVSS v3.1

EPSS:0.02%probability of exploitation in 30 daysPercentile:4.2th

Official Description

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.

NVD Source

Technical Analysis

CVE-2026-39816 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.8.