CVE-2026-81866: apache software foundation apache nifi Missing Authorization
Vulnerability summary
CVE-2026-81866 is a medium (CVSS 4.3) Missing Authorization vulnerability in apache software foundation apache nifi. EPSS estimates a 0.56% chance of exploitation in the next 30 days, higher than 45.7% of scored vulnerabilities.
Timeline
- 16-09-2026PublishedVulnerability first disclosed.
- 17-09-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
3 scores · 2 sources · 2 versions- NVDNIST0.5LowCVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:N/AU:Y/R:U/V:C/RE:L/U:Clear
EPSS trend
Probability
0.56%
Chance of exploitation in the next 30 days
Percentile
46%
Versus all other CVEs
30-day change
+0.16 pp
From 0.40% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Apache1 product
- nifi≥ 2.9.0, < 2.12.0
Apache software foundation1 product
- apache nifi≥ 2.9.0, ≤ 2.11.0
2 vendors · 2 products