External risk intelligence

Apache Nutch REST API Missing Authorization and Resource Handling Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.1)

CVE-2026-41869

The Apache Nutch REST API is a server-side component. While typically deployed in internal networks for administrative tasks, configurations vary widely. Because it lacks built-in authorization, any instance inadvertently exposed to the internet via misconfiguration or proxy error becomes directly accessible to remote attackers.

Apache Nutch

1.10 to before 1.23

Halo Surface Signal: 3 out of 5 — possibly public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A security vulnerability has been identified in the Apache Nutch Server's REST API, impacting versions from 1.10 through 1.22. This issue relates to how the server manages resources and handles interruptions, potentially allowing unauthorized access and denial-of-service conditions. The main concern is to confirm if our environment utilizes these specific versions of Apache Nutch, as the recommended mitigation involves removing the Nutch Server component or restricting access to trusted users.

Unsecured Nutch server allows unauthorized access and service interruption.
Critical vulnerability impacts Apache Nutch server components.
Verify Nutch usage and restrict access if necessary.

Attack Path

How an attacker could exploit the issue

An attacker could reach the vulnerable Apache Nutch Server's REST API from the network without any authentication. This vulnerability could allow an attacker to cause a denial of service or potentially access sensitive information.

Accessible over the network without authentication.
Triggers via the Nutch REST API.
Potential for data access or denial of service.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability in the Apache Nutch Server's REST API could allow an unauthenticated attacker to access and potentially disrupt server-side resources. This risk is present when the Nutch server is accessible over a network and not adequately protected by network access controls.

Server resources and job interruption.
Unauthenticated network access to the API.
Potential data exposure and service disruption.

Operational Fix

Recommended remediation, mitigation, and detection steps

Real-world ownership for this vulnerability likely falls to the team managing the Apache Nutch service, which could be an application, platform, or infrastructure team. The immediate first step is to identify all Nutch server instances, assess their exposure and business criticality, and confirm the accountable owner. Remediation planning should then be prioritized based on this risk assessment.

Application or platform team ownership.
Verify Nutch instance exposure and criticality.
Plan remediation based on risk.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is Apache Nutch?

Apache Nutch is an open-source, Java-based web crawler software. Organizations use it to index web content and gather data from across the internet or private intranets. The Nutch Server component specifically provides a REST API that allows users to remotely manage and monitor crawling jobs.

What does CVE-2026-41869 mean?

This CVE represents a security flaw involving Missing Authorization (CWE-862) and Improper Resource Shutdown (CWE-404). In plain terms, the server fails to verify who is making a request and does not safely manage its own processes, which can allow unauthorized users to stop tasks or potentially view data.

How is this vulnerability triggered?

An attacker triggers this issue by sending unauthenticated requests directly to the Nutch REST API over a network. It is important to note that performing routine crawling tasks or using Nutch's web search features does not trigger this bug; the vulnerability is specific to the exposed management interface.

Do I need to worry if my Nutch instance is internal?

Halo Surface Signal indicates that while the Nutch REST API is often used for internal administration, its security depends entirely on network placement. If a misconfiguration or proxy error makes your instance reachable from the internet, it becomes accessible to remote attackers without requiring login credentials.

When should I take action to secure my Nutch server?

You should prioritize this immediately by identifying all running Nutch server instances in your environment. The most effective step is to upgrade to version 1.23, which removes the vulnerable server component entirely. If an upgrade is not immediately possible, you must restrict network access to the service so that only trusted users can reach it.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.