Apache Nutch: Unauthenticated reflection-based job execution in Nutch Server (Nutch REST API)

published 2026-09-09 2 mo ago modified 2026-09-10 59 d ago also EUVD-2026-74803

cvss: 9.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.7%; EPSS 0.7% chance of exploitation in 30 days, percentile 55%
public exploits: 0; none known

Missing Authorization, Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection') vulnerability in Apache Nutch Server (Nutch REST API).

This issue affects Apache Nutch: from 1.10 through 1.22.

Users are recommended to upgrade to version 1.23, which removes the Nutch Server. If an upgrade is not possible, user must restrict access to instances running the Nutch Service to trusted users only. Please, also visit the Apache Nutch security advisories https://nutch.apache.org/documentation/security/ .

Patch / fix

fixed in 1

apache nutch 1.23

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: total
Assessed: 59 d ago (2026-09-10)

Exploit prediction

0.74% chance of exploitation in the next 30 days, higher than 55% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Apache Software Foundation Apache Nutch

Classification

Weakness

CWE-862 Missing Authorization
CWE-470 Use of Externally-Controlled Input to Select Classes or Code

References

lists.apache.org /thread/rbr63fx8vlrhzrfknq2l0mg0d0blsl54
vendor-advisory, mailing-list
openwall.com /lists/oss-security/2026/09/08/5
mailing-list, third-party-advisory

Sources

CVE List CVE-2026-41871
NVD CVE-2026-41871

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary