CVE-2026-63317: Arbitrary Class Instantiation via XML Feature Generator Descriptor and Format Name in Apache OpenNLP Versions

Q: How do I fix CVE-2026-63317?

opennlp: upgrade to 2.5.11. Exact commands for each OS are on this page.

Q: Is CVE-2026-63317 being exploited?

CVE-2026-63317 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-63317 affect?

CVE-2026-63317 affects opennlp. Severity is medium (CVSS 5.6). Arbitrary Class Instantiation via XML Feature Generator Descriptor and Format Name in Apache OpenNLP Versions Affected: - before 2.5.10 - before 3.0.0-M5 Description: Three code paths in Apache OpenNLP load a class by its fully-qualif

Q: How urgent is CVE-2026-63317?

Priority 44/100. Remotely exploitable, no login, no user action; On your watchlist

This month

MEDIUM 5.6REMOTEWATCHLISTUPGRADE

CVE-2026-63317 is a medium-severity flaw (CVSS 5.6) affecting opennlp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Arbitrary Class Instantiation via XML Feature Generator Descriptor and Format Name in Apache OpenNLP Versions Affected: - before 2.5.10 - before 3.0.0-M5 Description: Three code paths in Apache OpenNLP load a class by its fully-qualified name via Class.forName() and invoke its no-arg constructor without any prior validation of the class name or its type. The affected paths are: (1) GeneratorFactory, which reads the class attribute of ge

Why this priority

Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	5.6 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.9% (top 42%)
CISA exploited list	No
Weakness	CWE-470
Published	2026-07-24
Last modified	2026-10-24

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

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-24 09:16 UTCPublished CVE record published
2026-10-24 13:10 UTCUpdated Record last modified

apache opennlp UPGRADE

Affected: < 2.5.11 · 3.0.0 m1 · 3.0.0 m2 · 3.0.0 m3

Fixed in: 2.5.11

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 2.5.11 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade opennlp

Note

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

Exact fixes by distribution

Fedora 46 · gnome-shell-extension-tiling-assistant · FIXED · 56-1.fc46 · FEDORA-2026-ebf66a5321 · source

sudo dnf upgrade --advisory=FEDORA-2026-ebf66a5321

Debian 12 · apache-opennlp · NO FIX YET

Debian 13 · apache-opennlp · NO FIX YET

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-2026-63317?

opennlp: upgrade to 2.5.11. Exact commands for each OS are on this page.

Is CVE-2026-63317 being exploited?

CVE-2026-63317 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-2026-63317 affect?

CVE-2026-63317 affects opennlp. Severity is medium (CVSS 5.6). Arbitrary Class Instantiation via XML Feature Generator Descriptor and Format Name in Apache OpenNLP Versions Affected: - before 2.5.10 - before 3.0.0-M5 Description: Three code paths in Apache OpenNLP load a class by its fully-qualif

How urgent is CVE-2026-63317?

Priority 44/100. Remotely exploitable, no login, no user action; On your watchlist

References

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