CVE-2026-40682

The Apache OpenNLP DictionaryEntryPersistor component is vulnerable to XML External Entity (XXE) injection in versions prior to 2.5.9 and 3.0.0-M3 . The root cause is that the DictionaryEntryPersistor class initializes a static SAXParserFactory at class-load time without enabling FEATURE_SECURE_P...

CVE-2026-42440

Apache OpenNLP is vulnerable to an Out-of-Memory (OOM) Denial of Service in the AbstractModelReader component. The methods getOutcomes(), getOutcomePatterns(), and getPredicates() read a 32-bit signed integer count from a binary model stream and pass it directly to array allocations without valid...

CVE-2026-42027

Apache OpenNLP is vulnerable to arbitrary class instantiation via its ExtensionLoader component in versions before 1.9.5, 2.5.9, and 3.0.0-M3. The instantiateExtension method uses Class.forName() to load classes based on the manifest.properties entry of a model archive. Because the type check occ...

CVE-2026-63317

Apache OpenNLP versions before 2.5.10 and before 3.0.0-M5 are vulnerable to arbitrary class instantiation because three code paths use Class.forName() to load classes without prior validation. Specifically, GeneratorFactory parses class names from XML descriptors in model archives, StreamFactoryR...