VULNOS
All Threat Alerts
criticalCVE Alert
CVE-2026-40682

Critical Vulnerability: CVE-2026-40682 — apache — opennlp

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 r

Thursday, May 14, 2026apacheVulnios Threat Intelligence
Share:

Vulnerability Snapshot

CVE-2026-40682 is rated CRITICAL — exploitation is trivial or already observed in the wild and impact is severe. Patch immediately, not on the next maintenance window.

Affected technology: opennlp.

Executive Summary

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 dis

Why It Matters

CVE-2026-40682 is rated CRITICAL severity, requiring immediate attention from security teams.

CVSS Base Score: 9.1/10

Affected Technologies

Vendors: apache

Products: opennlp

🛡️What Defenders Should Check

  • Check if you are affected — Review your asset inventory for products listed in CVE-2026-40682.
  • Apply available patches — Visit vendor advisories for the latest security updates.
  • Monitor for exploitation — Check your SIEM/IDS logs for related indicators.

    • Use Vulnios to continuously monitor your exposure to CVE-2026-40682 and similar vulnerabilities.

    References & Sources

  • https://lists.apache.org/thread/r6jpt0qr9nj67gqhppqg7jxf8vsbo0w6
  • http://www.openwall.com/lists/oss-security/2026/05/01/19

    • How Vulnios Detects This

    Vulnios scans for this vulnerability using Trivy and Grype for CVE matching against your container images and OS package manifests and Nuclei templates that probe live HTTP surfaces for the published exploit pattern. Run a scan against your environment to see whether you are exposed; findings are linked back to the original CVE record so triage starts with the patch path already known.

    AI Security Advisor

    Powered by Gemini

    Get AI-powered security recommendations tailored to this specific threat — including risk assessment, detection guidance, MITRE ATT&CK mapping, and actionable remediation steps.

    Affected Products

    opennlp

    Sources

    Related Threat Alerts

    Frequently Asked Questions

    What is CVE-2026-40682?

    CVE-2026-40682 is a critical-severity vulnerability tracked under the Common Vulnerabilities and Exposures program. 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 c

    Am I affected?

    Check whether your environment runs opennlp. If you operate any of those, treat yourself as in scope until you have evidence otherwise. A Vulnios scan will identify the exact assets carrying the affected version.

    How urgent is the response?

    Critical: do not wait for your normal patch cycle. Verify exposure today, apply the vendor patch immediately, and add detection rules for any post-exploit indicators.

    How do I remediate?

    Apply the vendor patch listed in the upstream advisory linked under Sources. If the patch is not yet available, follow the vendor-supplied workaround (often a config flag or feature disable) and add detections for the published exploit pattern in your SIEM. Re-scan after the patch lands to confirm the finding clears.

    Where can I track exploitation activity?

    Watch CISA's Known Exploited Vulnerabilities catalog for CVE-2026-40682. Cross-reference with public exploit databases and your own SIEM/IDS for indicator-of-compromise patterns. Vulnios tracks KEV status automatically and surfaces it on the asset findings view.

    How does Vulnios help with this?

    Vulnios continuously cross-references your asset inventory against the live CVE feed (NVD, vendor advisories, CISA KEV, and curated OSINT). When a new CVE matches your environment, you get a prioritized finding with the severity, KEV status, exploit-prediction (EPSS), and a direct path to the vendor patch. You can start a free scan from the homepage.

    critical

    Protect Your Organization

    Monitor CVEs, scan for vulnerabilities, and get real-time threat alerts — all in one platform.

    Get Started FreeFree Security ScanOSINT Dashboard

    Get instant alerts on Telegram

    Join our public channel for real-time critical CVE alerts.

    Follow @vulnios