CVE-2026-44911: Apache NiFi Auth Bypass Vulnerability

CVE-2026-44911 Overview

CVE-2026-44911 is an authorization vulnerability [CWE-863] affecting Apache NiFi versions 1.15.0 through 2.9.0. The flaw resides in the authorization handling for component configuration verification requests. Clients holding only read access can submit proposed configuration properties that override the current configuration. This allows users with read-only privileges to invoke predefined verification methods using attacker-controlled settings.

Installations that do not differentiate authorization levels between viewing and modifying component configuration are not affected. Apache addressed the issue in NiFi 2.10.0 by requiring write access to submit configuration verification requests.

Critical Impact
Authenticated users with read-only access can trigger component verification methods with arbitrary configuration values, bypassing the intended separation between read and write permissions.

Affected Products

Apache NiFi 1.15.0 through 1.x latest
Apache NiFi 2.0.0 through 2.9.0
Deployments enforcing distinct read versus modify authorization policies on components

Discovery Timeline

2026-06-22 - CVE-2026-44911 published to NVD
2026-06-23 - Last updated in NVD database

Technical Details for CVE-2026-44911

Vulnerability Analysis

Apache NiFi exposes component configuration verification endpoints that allow operators to validate processor, controller service, and reporting task settings before applying them. The verification workflow accepts a set of proposed properties and invokes predefined verification routines against the target component.

In versions 1.15.0 through 2.9.0, the endpoint enforces only read-level authorization on the target component. Clients with read access can submit proposed properties that temporarily override the current configuration. This contradicts the principle that modifying behavior, even transiently for verification, should require write authorization.

The practical impact depends on what each component's verification method does. Verification routines commonly establish outbound connections, resolve credentials, query remote services, or evaluate expressions against supplied parameters. A read-only user can therefore coerce the server into performing these actions with attacker-supplied values.

Root Cause

The root cause is incorrect authorization [CWE-863] on the verification request handler. The endpoint validates that the caller can view the component but does not require write permission before accepting client-supplied configuration overrides. Read and write privileges are treated equivalently for this code path.

Attack Vector

An authenticated user with read access to a component sends a verification request over the network containing proposed configuration properties. The server accepts the override, invokes the component's verification logic, and returns the result. No user interaction is required beyond the attacker's own authenticated session. Installations that grant identical read and write policies to all users are not exposed by this flaw, since no privilege boundary exists to bypass.

The vulnerability is described as an authorization handling weakness. Refer to the Apache Mailing List Discussion and the OpenWall OSS-Security Update for vendor-confirmed technical details.

Detection Methods for CVE-2026-44911

Indicators of Compromise

HTTP requests to NiFi verification endpoints such as /nifi-api/processors/{id}/config/verification-requests or equivalent controller-service and reporting-task paths from accounts that hold only read policies.
Verification requests containing properties payloads that differ from the component's stored configuration.
Outbound network connections initiated by the NiFi JVM to unexpected hosts shortly after verification API calls.

Detection Strategies

Correlate NiFi audit logs with the user's effective policy set, alerting when verification requests originate from principals lacking write authorization on the target component.
Inspect reverse proxy or API gateway logs for POST traffic to /verification-requests paths and baseline expected callers.
Review NiFi nifi-user.log and nifi-app.log for verification request entries paired with policy lookups returning read-only results.

Monitoring Recommendations

Forward NiFi audit, application, and access logs to a centralized analytics platform for retention and query.
Alert on any verification request submitted with properties overrides outside an approved change window.
Monitor the NiFi host for new outbound connections to non-allowlisted destinations following verification API activity.

How to Mitigate CVE-2026-44911

Immediate Actions Required

Upgrade Apache NiFi to version 2.10.0, which requires write access for component configuration verification requests.
Inventory all NiFi instances and confirm versions; treat any deployment between 1.15.0 and 2.9.0 as affected.
Review user and group policies to confirm that read and write permissions are intentionally separated on sensitive components.

Patch Information

Apache fixed CVE-2026-44911 in Apache NiFi 2.10.0. The patched release enforces write authorization on the verification request handler, so read-only clients can no longer submit proposed property overrides. Release details are documented in the Apache Mailing List Discussion.

Workarounds

Align read and write component policies for all users until the upgrade is applied; the vulnerability does not apply when no privilege distinction exists.
Restrict network access to NiFi API endpoints to trusted operator networks using firewall or reverse proxy rules.
Audit and reduce the number of accounts holding read access to components whose verification routines interact with credentials or external systems.

bash

# Verify the installed Apache NiFi version
cat $NIFI_HOME/lib/nifi-runtime-*.jar | head -1
$NIFI_HOME/bin/nifi.sh status

# Upgrade path: stop the service, deploy 2.10.0, migrate configuration
$NIFI_HOME/bin/nifi.sh stop
# Replace binaries with Apache NiFi 2.10.0 distribution
$NIFI_HOME/bin/nifi.sh start