CVE-2026-78214: Apache DolphinScheduler Auth Bypass Vulnerability

CVE-2026-78214 Overview

CVE-2026-78214 is an authentication bypass vulnerability affecting Apache DolphinScheduler versions prior to 3.4.3. The flaw exists in the authorization logic protecting Spring Boot Actuator endpoints. The application matches incoming request paths against a list of protected Actuator paths to determine whether authentication is required. A remote unauthenticated attacker can submit a request containing a percent-encoded path that the security check fails to recognize as protected. The attacker then reaches Actuator endpoints that should require authentication, potentially exposing operational and configuration data. This weakness is categorized under CWE-863: Incorrect Authorization.

Critical Impact

Unauthenticated remote attackers can access management endpoints and disclose operational or configuration information, with further impact depending on which Actuator endpoints are enabled.

Affected Products

• Apache DolphinScheduler versions prior to 3.4.3
• Deployments exposing Actuator endpoints over the network
• Installations relying on the built-in path-matching security check

Discovery Timeline

• 2026-09-29 - CVE CVE-2026-78214 published to NVD
• 2026-09-29 - Last updated in NVD database

Technical Details for CVE-2026-78214

Vulnerability Analysis

Apache DolphinScheduler protects Actuator endpoints by comparing the request path against a predefined list of sensitive paths. The comparison operates on the raw request URI rather than the normalized, decoded path used later during endpoint dispatch. This inconsistency creates a parser differential between the security filter and the underlying servlet routing layer.

An attacker who percent-encodes characters in the path submits a URI that the security filter does not classify as an Actuator request. The Spring dispatcher, however, decodes the URI and routes it to the intended Actuator handler. The request bypasses the authentication check and reaches the management endpoint directly.

Depending on which endpoints are exposed, an attacker may retrieve environment variables, configuration properties, health details, thread dumps, or metrics. Some Actuator endpoints reveal credentials embedded in configuration, while others expose internal service topology useful for follow-on attacks.

Root Cause

The root cause is inconsistent URI normalization between the authorization layer and the request dispatcher. The path-matching check does not canonicalize percent-encoded sequences before comparing them to the protected path list. This design failure maps to CWE-863: Incorrect Authorization.

Attack Vector

Exploitation requires only network access to the DolphinScheduler HTTP interface. The attacker crafts an HTTP GET request in which one or more characters in the /actuator/ path segment are replaced with their percent-encoded equivalents. The security filter fails to match the encoded path against its protected list, and the request passes through to the Actuator handler. No credentials, user interaction, or prior foothold are required. Refer to the Apache Mailing List Thread and the OpenWall OSS Security Update for the vendor advisory details.

Detection Methods for CVE-2026-78214

Indicators of Compromise

• HTTP requests to DolphinScheduler containing percent-encoded characters within the /actuator path segment, such as %61ctuator or /%2561ctuator/env.
• Successful 200 OK responses to unauthenticated requests targeting Actuator endpoints like /env, /configprops, /heapdump, or /mappings.
• Access log entries showing Actuator responses without a preceding authenticated session.

Detection Strategies

• Inspect web server and reverse proxy logs for URI patterns containing % sequences directed at actuator paths.
• Compare authorization decisions against dispatched handlers to identify parser differentials between filters and routing.
• Alert on any unauthenticated 2xx response from paths resolving to Spring Boot Actuator endpoints.

Monitoring Recommendations

• Enable verbose access logging on DolphinScheduler and any fronting proxy, capturing the raw request URI.
• Forward web tier logs to a centralized analytics platform and build queries for Actuator path variants.
• Monitor outbound traffic from DolphinScheduler hosts for anomalous connections that could indicate follow-on exploitation using leaked configuration data.

How to Mitigate CVE-2026-78214

Immediate Actions Required

• Upgrade Apache DolphinScheduler to version 3.4.3 or later, which corrects the path-matching logic.
• Restrict network access to DolphinScheduler management interfaces to trusted administrative networks only.
• Audit currently enabled Actuator endpoints and disable those not required for operations.
• Rotate any credentials, tokens, or secrets that may have been exposed through Actuator endpoints prior to patching.

Patch Information

The Apache DolphinScheduler project addresses this issue in version 3.4.3. Users on any earlier release should upgrade. Vendor details are available in the Apache Mailing List Thread and the OpenWall OSS Security Update.

Workarounds

• Block requests containing percent-encoded characters in the /actuator path at an upstream reverse proxy or web application firewall.
• Disable non-essential Actuator endpoints in DolphinScheduler configuration until the upgrade is applied.
• Enforce network-level access control lists limiting connectivity to the DolphinScheduler management port.

# Example NGINX rule to block percent-encoded actuator paths
location ~* "/%[0-9a-fA-F]{2}" {
    if ($request_uri ~* "actuator") {
        return 403;
    }
}