CVE-2026-81866: Auth Bypass

Description

Apache NiFi 2.9.0 through 2.11.0 provide Connector configuration update and verification REST API methods that do not enforce authorization checking on Assets and Secrets referenced in proposed configuration. Updating or verifying a Connector configuration step can apply Asset and Secret references, but framework authorization was limited to write privileges on the Connector itself. As a result of the missing authorization, an authenticated user authorized to modify a Connector, but not authorized to read a referenced Parameter Provider, could apply Secret values backed by that Parameter Provider. The same methods also accepted Asset identifiers without verifying that the Asset belonged to the Connector being configured. Apache NiFi installations that do not implement different levels of authorization across Connectors and Parameter Providers are not subject to this vulnerability, because the framework enforces write permissions on the Connector as the security boundary. Upgrading to Apache NiFi 2.12.0 is the recommended mitigation, which authorizes read access to referenced Parameter Providers and verifies Connector ownership of referenced Assets during configuration update and verification.

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Weakness Type (CWE)

CWE-862 Missing Authorization

References

Other References

https://lists.apache.org/thread/rv49gwf4yb00ykv0zzfd509boxflolsf http://www.openwall.com/lists/oss-security/2026/09/16/8

Frequently Asked Questions

What is CVE-2026-81866? +

Apache NiFi 2.9.0 through 2.11.0 provide Connector configuration update and verification REST API methods that do not enforce authorization checking on Assets and Secrets referenced in proposed configuration. Updating or verifying a Connector configuration step can apply Asset and Secret references, but framework authorization was limited to write privileges on the Connector itself. As a result of the missing authorization, an authenticated user authorized to modify a Connector, but not authorized to read a referenced Parameter Provider, could apply Secret values backed by that Parameter Provider. The same methods also accepted Asset identifiers without verifying that the Asset belonged to the Connector being configured. Apache NiFi installations that do not implement different levels of authorization across Connectors and Parameter Providers are not subject to this vulnerability, because the framework enforces write permissions on the Connector as the security boundary. Upgrading to Apache NiFi 2.12.0 is the recommended mitigation, which authorizes read access to referenced Parameter Providers and verifies Connector ownership of referenced Assets during configuration update and verification.

How do I check if I'm vulnerable to CVE-2026-81866? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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