DEBIAN-CVE-2026-42027
Arbitrary Class Instantiation via Model Manifest in Apache OpenNLP ExtensionLoader Versions Affected: before 1.9.5, before 2.5.9, before 3.0.0-M3 Description: The ExtensionLoader.instantiateExtension(Class, String) method loads a class by its fully-qualified name via Class.forName() and invokes its no-arg constructor, with the class name sourced from the manifest.properties entry of a model archive. The existing isAssignableFrom check correctly rejects classes that are not subtypes of the expected extension interface (BaseToolFactory for factory=, ArtifactSerializer for serializer-class-*), but the check runs after Class.forName() has already loaded and initialized the named class. Class.forName() with default initialization semantics executes the target class's static initializer before returning, so an attacker who can supply a crafted model archive can cause the static initializer of any class on the classpath to run during model loading, regardless of whether that class passes the subsequent type check. Exploitation requires a class with attacker-useful side effects in its static initializer (for example, JNDI lookup, outbound network I/O, or filesystem access) to be present on the classpath, so this is not a drop-in remote code execution; however, the attack surface grows as third-party model distribution becomes more common (community model repositories, Hugging Face-style sharing), where users routinely load model files from origins they do not control. A secondary, na
DEBIAN-CVE-2026-42027
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:DEBIAN-CVE-2026-42027
apache-opennlp
Source reference: /affected/0/package/name
- Affected versions
- 2.1.0-1
Source reference:
/affected/0/versions2.2.0-1Source reference:
/affected/0/versions2.2.0-1~expSource reference:
/affected/0/versions2.3.0-1Source reference:
/affected/0/versions2.3.1-1Source reference:
/affected/0/versions2.3.1-2Source reference:
/affected/0/versions2.3.2-1Source reference:
/affected/0/versions2.3.3-1Source reference:
/affected/0/versions2.4.0-1Source reference:
/affected/0/versions2.5.0-1Source reference:
/affected/0/versions2.5.1-1Source reference:
/affected/0/versions2.5.12-1Source reference:
/affected/0/versions2.5.2-1Source reference:
/affected/0/versions2.5.3-1Source reference:
/affected/0/versions2.5.9-1Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
apache-opennlp
Source reference: /affected/1/package/name
- Affected versions
- 2.5.12-1
Source reference:
/affected/1/versions2.5.3-1Source reference:
/affected/1/versions2.5.9-1Source reference:
/affected/1/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
apache-opennlp
Source reference: /affected/2/package/name
- Affected versions
- 2.5.3-1
Source reference:
/affected/2/versions - Fixed versions
- 2.5.9-1
Source reference:
/affected/2/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "apache-opennlp",
"purl": "pkg:deb/debian/apache-opennlp?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"2.1.0-1",
"2.2.0-1",
"2.2.0-1~exp",
"2.3.0-1",
"2.3.1-1",
"2.3.1-2",
"2.3.2-1",
"2.3.3-1",
"2.4.0-1",
"2.5.0-1",
"2.5.1-1",
"2.5.12-1",
"2.5.2-1",
"2.5.3-1",
"2.5.9-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-42027.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "apache-opennlp",
"purl": "pkg:deb/debian/apache-opennlp?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"2.5.12-1",
"2.5.3-1",
"2.5.9-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-42027.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.5.9-1"
}
]
}
],
"package": {
"name": "apache-opennlp",
"purl": "pkg:deb/debian/apache-opennlp?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"2.5.3-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-42027.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #56961 · Revision 1
- Added to Heist Feed
- Publisher date