XML External Entity Vulnerability in Apache OpenNLP by Apache
CVE-2026-40682

9.1CRITICAL

Key Information:

Vendor

Apache
Status
Apache Opennlp
Vendor
CVE Published:
4 May 2026

What is CVE-2026-40682?

The DictionaryEntryPersistor class in Apache OpenNLP is vulnerable due to improper SAX parser configuration, enabling external entity resolution and DTD processing. This allows attackers to exploit crafted dictionary files, potentially leading to local file disclosures or server-side request forgery. Users are advised to upgrade to the latest versions for mitigation, and ensure dictionary files are from trusted sources to minimize risk.

Affected Version(s)

Apache OpenNLP 2.0 < 2.5.9

Apache OpenNLP 3.0.0-M1 < 3.0.0-M3

Apache OpenNLP 0 < 1.9.5

References

https://lists.apache.org/thread/r6jpt0qr9nj67gqhppqg7jxf8...
vendor-advisory

CVSS V3.1

Score:
9.1
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Subramanian S
.