CVE-2026-81866

MEDIUMNVD 4.34.3—
EchelonGraph scoreHIGH confidence

Score 4.3 from GitHub Security Advisory (severity: LOW) published 2026-09-16. NVD baseline CVSS 4.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 4 sources updated this week
4.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 4.3Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
4.3
EG Score
4.3(high)
EG Risk
20(Track)
EG Risk 20/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity43% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
44%
KEV
Not listed

Published

September 16, 2026

Last Modified

September 21, 2026

Advisory Details (2)

Auto-updated Sep 21, 2026
No patch confirmed yet.
generic

oss-security - CVE-2026-81866: Apache NiFi: Missing Authorization for Assets and Secrets Referenced by Connector Configuration

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

Vendor Advisories for CVE-2026-81866(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 19× in last 7d / 26× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-25 05:06 UTCEG score recompute
  2. 2026-09-25 05:06 UTCGHSA enrichment
  3. 2026-09-24 14:04 UTCEPSS rescore
  4. 2026-09-24 07:15 UTCEG score recompute
  5. 2026-09-24 07:15 UTCGHSA enrichment
  6. 2026-09-23 17:54 UTCEPSS rescore
  7. 2026-09-23 09:25 UTCEG score recompute
  8. 2026-09-23 09:25 UTCGHSA enrichment
  9. 2026-09-22 16:01 UTCEPSS rescore
  10. 2026-09-22 11:34 UTCEG score recompute
  11. 2026-09-22 11:34 UTCGHSA enrichment
  12. 2026-09-21 21:09 UTCEPSS rescore
  13. 2026-09-21 13:44 UTCEG score recompute▲ 3.80
  14. 2026-09-21 13:44 UTCGHSA enrichment
  15. 2026-09-21 13:39 UTCNVD updateCVSS v3 → 4.3 · severity → MEDIUM
  16. 2026-09-20 20:16 UTCEPSS rescore
  17. 2026-09-20 12:25 UTCEG score recompute
  18. 2026-09-20 12:25 UTCGHSA enrichment
  19. 2026-09-18 19:28 UTCEPSS rescore
  20. 2026-09-17 13:22 UTCEG score recompute
  21. 2026-09-17 13:22 UTCGHSA enrichment
  22. 2026-09-17 12:53 UTCEG score recompute
  23. 2026-09-17 12:53 UTCGHSA enrichment
  24. 2026-09-16 21:00 UTCEG score recompute
  25. 2026-09-16 19:44 UTCEG score recompute
Show 1 more
  1. 2026-09-16 19:44 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-81866?
CVE-2026-81866 is a medium vulnerability published on September 16, 2026. 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…
When was CVE-2026-81866 disclosed?
CVE-2026-81866 was first published in the National Vulnerability Database on September 16, 2026, with the most recent update on September 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-81866 actively exploited?
CVE-2026-81866 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 55.5% of all scored CVEs.
What is the CVSS score of CVE-2026-81866?
CVE-2026-81866 has a CVSS v3 base score of 4.3 (NVD).
How do I remediate CVE-2026-81866?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-81866, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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