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CVE-2026-40682
Published:May 04, 2026
Updated:May 16, 2026
XML External Entity (XXE) via Unsanitized Dictionary Parsing in Apache OpenNLP DictionaryEntryPersistor Versions Affected: before 2.5.9, before 3.0.0-M3 Description: The DictionaryEntryPersistor class initializes a static SAXParserFactory at class-load time without enabling FEATURE_SECURE_PROCESSING or disabling DTD processing. When create(InputStream, EntryInserter) is invoked, the only feature set on the XMLReader is namespace support — external entity resolution and DOCTYPE declarations remain fully enabled. An attacker who can supply a crafted dictionary file (e.g., a stop-word list or domain dictionary) containing a malicious DOCTYPE declaration can trigger local file disclosure via file:// entity references or server-side request forgery via http:// entity references during SAX parsing, before the application processes a single dictionary entry. This is inconsistent with the project's own XmlUtil.createSaxParser() helper, which correctly sets FEATURE_SECURE_PROCESSING and disallow-doctype-decl and is used by all other XML parsing paths in the codebase. The public Dictionary(InputStream) constructor delegates directly to this method and is the documented API for loading user-supplied dictionaries, making untrusted input a realistic scenario. Mitigation: 2.x users should upgrade to 2.5.9. 3.x users should upgrade to 3.0.0-M3. Users who cannot upgrade immediately should ensure that all dictionary files are sourced from trusted origins and should consider wrapping the Dictionary(InputStream) constructor with input validation that rejects any XML containing a DOCTYPE declaration before it reaches the parser.
Affected Packages
https://github.com/apache/opennlp.git (GITHUB):
Affected version(s) >=opennlp-3.0.0-M1 <opennlp-3.0.0-M3
Fix Suggestion:
Update to version opennlp-3.0.0-M3
https://github.com/apache/opennlp.git (GITHUB):
Affected version(s) >=opennlp-2.5.0 <opennlp-2.5.9
Fix Suggestion:
Update to version opennlp-2.5.9
org.apache.opennlp:opennlp-tools (JAVA):
Affected version(s) >=2.5.0 <2.5.9
Fix Suggestion:
Update to version 2.5.9
org.apache.opennlp:opennlp-tools (JAVA):
Affected version(s) >=3.0.0-M1 <3.0.0-M3
Fix Suggestion:
Update to version 3.0.0-M3
org.apache.opennlp:opennlp-tools (JAVA):
Affected version(s) >=1.5.1-incubating <2.5.9
Fix Suggestion:
Update to version 2.5.9
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CVSS v4
Base Score:
6.9
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Improper Restriction of XML External Entity Reference
EPSS
Base Score:
0.11