CVE intelligence and bounded remediation

CVE-2026-40682 — Apache Opennlp security vulnerability

Critical CVSS 9.1

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…

Severity
Critical
CVSS
9.1 (3.1)
Published
2026-05-04
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-611

Affected products

  • apache / opennlp
  • apache / opennlp / 3.0.0

Showing 2 representative product identities from 3 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

XML external entity and unsafe XML processing

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Inventory XML parsers used by APIs, file imports, office or image formats, identity protocols, feeds, and background jobs.
  • Determine whether document type declarations, external entities, XInclude, schemas, or network resolvers are enabled.
  • Map parser filesystem and network access and the sensitivity of documents it processes.

Remediate safely

  • Configure each parser to reject document type declarations and disable external entity, XInclude, and network resolution features.
  • Prefer a data format or hardened parser that does not support external resolution, and apply input size and depth limits.
  • Update affected XML libraries and centralize secure parser construction so callers cannot silently override it.

Authoritative sources

Complete CVE record and remediation plan

The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.