CVE-2026-41871: Missing Authorization, Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection') vuln

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CRITICAL 9.8REMOTEWATCHLISTUPGRADE

CVE-2026-41871 is a critical-severity flaw (CVSS 9.8) affecting nutch. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

Critical severity
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 45%)
CISA exploited list	No
Weakness	CWE-470, CWE-862
Published	2026-09-09
Last modified	2026-09-10

Publisher (CNA): Apache Software Foundation · Vendor: apache

Last updated 2026-09-10 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-09 11:17 UTCPublished CVE record published
2026-09-10 20:38 UTCUpdated Record last modified

apache nutch UPGRADE

Affected: >= 1.10 and < 1.23

Fixed in: 1.23

Safe to downgrade to: a release before 1.10

1. Check installed version

apt-cache policy nutch || rpm -q nutch || nutch --version

2. UPGRADE to 1.23 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade nutch

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade nutch

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 1.10 (Debian / Ubuntu)

apt-cache madison nutch sudo apt install nutch=<VERSION_BEFORE_1.10> sudo apt-mark hold nutch

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list nutch sudo dnf downgrade nutch-<VERSION_BEFORE_1.10> sudo dnf versionlock add nutch

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

Fedora ELN · xfsdump · FIXED · 3.3.0-3.eln159 · FEDORA-2026-6e9bb3f901 · source

sudo dnf upgrade --advisory=FEDORA-2026-6e9bb3f901

Fedora 46 · fio · FIXED · 3.43-2.fc46 · FEDORA-2026-b36219886b · source

sudo dnf upgrade --advisory=FEDORA-2026-b36219886b

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-41871?

nutch: upgrade to 1.23. Exact commands for each OS are on this page.

Is CVE-2026-41871 being exploited?

CVE-2026-41871 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-41871 affect?

CVE-2026-41871 affects nutch. Severity is critical (CVSS 9.8). 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 recom

How urgent is CVE-2026-41871?

Priority 61/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action; On your watchlist

Related CVEs

CVE-2026-41870 HIGH 8.8 UPGRADE Missing Authorization, Improper Control of Generation of Code ('Code Injection'), Improper Control of Dynamica
CVE-2026-41869 CRITICAL 9.1 UPGRADE Missing Authorization, Improper Resource Shutdown and Job Interruption vulnerability in Apache Nutch Server (

References

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