apache-opennlp — security advisory
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 generator elements in an XML feature generator descriptor; such descriptors are embedded as artifacts in model archives (e.g. TokenNameFinder and POSTagger models) and are parsed during model loading, so an attacker who can supply a crafted model archive controls the class name directly. (2) StreamFactoryRegistry.getFactory(Class, String), which falls back to interpreting an unregistered format name as the fully-qualified class name of an ObjectStreamFactory; this is exploitable in applications that pass untrusted format names (e.g. exposing the -format parameter of the command-line tooling to external input). (3) StringInterners, which instantiates the interner implementation named by the opennlp.interner.class system property; this value is normally deployer-controlled, so it is hardened as defense in depth rather than being independently attacker-reachable. Exploitation requires a class with attacker-useful side effects in its static initializer or no-arg constructor (JNDI lookup, outbound network I/O, filesystem access) to be present on the c
- Products
- apache-opennlp
- Affected versions
- 1.9.1-2, 1.9.2-1, 1.9.3-1, 1.9.4-1, 2.3.0-1, 2.3.1-1, 2.3.1-2, 2.3.2-1, 2.5.3-1, 2.5.3-1build1, 2.5.9-1
- Fixed versions
- Not specified
- CVEs
- CVE-2026-63317
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 03:11 UTC · Revision 1
Source evidence
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 generator elements in an XML feature generator descriptor; such descriptors are embedded as artifacts in model archives (e.g. TokenNameFinder and POSTagger models) and are parsed during model loading, so an attacker who can supply a crafted model archive controls the class name directly. (2) StreamFactoryRegistry.getFactory(Class, String), which falls back to interpreting an unregistered format name as the fully-qualified class name of an ObjectStreamFactory; this is exploitable in applications that pass untrusted format names (e.g. exposing the -format parameter of the command-line tooling to external input). (3) StringInterners, which instantiates the interner implementation named by the opennlp.interner.class system property; this value is normally deployer-controlled, so it is hardened as defense in depth rather than being independently attacker-reachable. Exploitation requires a class with attacker-useful side effects in its static initializer or no-arg constructor (JNDI lookup, outbound network I/O, filesystem access) to be present on the c
osv:UBUNTU-CVE-2026-63317
apache-opennlp
Fixed versions: Not specified
apache-opennlp
Fixed versions: Not specified
apache-opennlp
Fixed versions: Not specified
apache-opennlp
Fixed versions: Not specified
apache-opennlp
Fixed versions: Not specified
Complete source record
{
"id": "bc091bd38b6f068cc372da587235c6c57829c02dcc03d40faccc5c7db7eb671b",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-63317",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-63317",
"summary": "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 generator elements in an XML feature generator descriptor; such descriptors are embedded as artifacts in model archives (e.g. TokenNameFinder and POSTagger models) and are parsed during model loading, so an attacker who can supply a crafted model archive controls the class name directly. (2) StreamFactoryRegistry.getFactory(Class, String), which falls back to interpreting an unregistered format name as the fully-qualified class name of an ObjectStreamFactory; this is exploitable in applications that pass untrusted format names (e.g. exposing the -format parameter of the command-line tooling to external input). (3) StringInterners, which instantiates the interner implementation named by the opennlp.interner.class system property; this value is normally deployer-controlled, so it is hardened as defense in depth rather than being independently attacker-reachable. Exploitation requires a class with attacker-useful side effects in its static initializer or no-arg constructor (JNDI lookup, outbound network I/O, filesystem access) to be present on the c",
"evidence": "osv:UBUNTU-CVE-2026-63317",
"products": [
{
"name": {
"value": "apache-opennlp",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.9.1-2",
"evidence": "/affected/0/versions"
},
{
"value": "1.9.2-1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "apache-opennlp",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.9.3-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.9.4-1",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "apache-opennlp",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.3.0-1",
"evidence": "/affected/2/versions"
},
{
"value": "2.3.1-1",
"evidence": "/affected/2/versions"
},
{
"value": "2.3.1-2",
"evidence": "/affected/2/versions"
},
{
"value": "2.3.2-1",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "apache-opennlp",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.5.3-1build1",
"evidence": "/affected/3/versions"
},
{
"value": "2.5.9-1",
"evidence": "/affected/3/versions"
}
]
},
{
"name": {
"value": "apache-opennlp",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.5.3-1",
"evidence": "/affected/4/versions"
},
{
"value": "2.5.3-1build1",
"evidence": "/affected/4/versions"
}
]
}
],
"severity": "medium",
"structured": {
"id": "UBUNTU-CVE-2026-63317",
"aliases": [
"UBUNTU-CVE-2026-63317"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "apache-opennlp",
"purl": "pkg:deb/ubuntu/apache-opennlp?arch=source&distro=focal",
"ecosystem": "Ubuntu:20.04:LTS"
},
"versions": [
"1.9.1-2",
"1.9.2-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63317.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libapache-opennlp-java",
"binary_version": "1.9.2-1"
},
{
"binary_name": "opennlp",
"binary_version": "1.9.2-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "apache-opennlp",
"purl": "pkg:deb/ubuntu/apache-opennlp?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
"1.9.3-1",
"1.9.4-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63317.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libapache-opennlp-java",
"binary_version": "1.9.4-1"
},
{
"binary_name": "opennlp",
"binary_version": "1.9.4-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "apache-opennlp",
"purl": "pkg:deb/ubuntu/apache-opennlp?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"2.3.0-1",
"2.3.1-1",
"2.3.1-2",
"2.3.2-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63317.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libapache-opennlp-java",
"binary_version": "2.3.2-1"
},
{
"binary_name": "opennlp",
"binary_version": "2.3.2-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "apache-opennlp",
"purl": "pkg:deb/ubuntu/apache-opennlp?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
"2.5.3-1build1",
"2.5.9-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63317.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libapache-opennlp-java",
"binary_version": "2.5.9-1"
},
{
"binary_name": "opennlp",
"binary_version": "2.5.9-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "apache-opennlp",
"purl": "pkg:deb/ubuntu/apache-opennlp?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"2.5.3-1",
"2.5.3-1build1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63317.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libapache-opennlp-java",
"binary_version": "2.5.3-1build1"
},
{
"binary_name": "opennlp",
"binary_version": "2.5.3-1build1"
}
]
}
}
],
"modified": "2026-10-17T13:00:31.893404759Z",
"provider": "osv",
"upstream": [
"CVE-2026-63317"
],
"references": [
"https://ubuntu.com/security/CVE-2026-63317",
"https://www.cve.org/CVERecord?id=CVE-2026-63317",
"https://lists.apache.org/thread/myr446n8t3gv8gq8wbpxm41olx16d8yj",
"https://issues.apache.org/jira/browse/OPENNLP-1890"
]
},
"related_cves": [
{
"value": "CVE-2026-63317",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 360664,
"published_at": "2026-07-24T09:16:00+00:00"
}