CVE-2026-47898: Improper Restriction of XML External Entity Reference vulnerability in Apache Lucene.Net (Lucene.Net.Analysis.

This month

CRITICAL 9.8REMOTEWATCHLISTDOWNGRADE

CVE-2026-47898 is a critical-severity flaw (CVSS 9.8) affecting lucene.net. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Improper Restriction of XML External Entity Reference vulnerability in Apache Lucene.Net (Lucene.Net.Analysis.Common library). This issue affects Apache Lucene.Net.Analysis.Common: from 4.8.0-beta00005 before 4.8.0-beta00018. Users are recommended to upgrade to version 4.8.0-beta00018, which fixes the issue.

Why this priority

Critical severity
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	0.5% (top 60%)
CISA exploited list	No
Weakness	CWE-611
Published	2026-07-03
Last modified	2026-10-25

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

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-03 08:16 UTCPublished CVE record published
2026-10-25 21:10 UTCUpdated Record last modified

apache lucene.net DOWNGRADE

Affected: 4.8.0 beta00005 · 4.8.0 beta00006 · 4.8.0 beta00007 · 4.8.0 beta00008 · 4.8.0 beta00009 · 4.8.0 beta00010 · 4.8.0 beta00011 · 4.8.0 beta00012

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.8.0

1. Check installed version

apt-cache policy lucene.net || rpm -q lucene.net || lucene.net --version

2. No fixed release: DOWNGRADE to a release before 4.8.0 (Debian / Ubuntu)

apt-cache madison lucene.net sudo apt install lucene.net=<VERSION_BEFORE_4.8.0> sudo apt-mark hold lucene.net

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list lucene.net sudo dnf downgrade lucene.net-<VERSION_BEFORE_4.8.0> sudo dnf versionlock add lucene.net

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

A distro patch exists: prefer upgrading over downgrading.

Fedora 46 · mingw-qt5-qtwebkit · FIXED · 5.212.0-0.46.alpha4.fc46 · FEDORA-2026-46ae541c22 · source

sudo dnf upgrade --advisory=FEDORA-2026-46ae541c22

Fedora ELN · kdominate · FIXED · 26.08.2-2.eln159 · FEDORA-2026-b1d98239fd · source

sudo dnf upgrade --advisory=FEDORA-2026-b1d98239fd

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-2026-47898?

lucene.net: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-47898 being exploited?

CVE-2026-47898 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-2026-47898 affect?

CVE-2026-47898 affects lucene.net. Severity is critical (CVSS 9.8). Improper Restriction of XML External Entity Reference vulnerability in Apache Lucene.Net (Lucene.Net.Analysis.Common library). This issue affects Apache Lucene.Net.Analysis.Common: from 4.8.0-beta00005 before 4.8.0-beta00018. Users are re

How urgent is CVE-2026-47898?

Priority 54/100. Critical severity; Remotely exploitable, no login, no user action; On your watchlist

Related CVEs

CVE-2026-47897 HIGH 7.5 DOWNGRADE Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in Apache Lucene.
CVE-2026-47896 HIGH 7.5 DOWNGRADE Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in Apache Lucene.

References

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