Security readout for executives and security teams
Plain-English summary
Apache OpenNLP can parse dictionary XML unsafely in affected versions. If an application accepts a malicious dictionary file, parsing may disclose local files or trigger server-side requests before normal dictionary processing begins.
Executive priority
Treat as urgent for systems that process external dictionary files. The issue is critical severity, but business urgency depends on whether untrusted parties can influence OpenNLP dictionary input.
Technical view
CVE-2026-40682 is an XXE flaw in DictionaryEntryPersistor. A SAXParserFactory is initialized without secure processing or DTD blocking, leaving external entity resolution enabled when Dictionary(InputStream) reaches the parser. Affects OpenNLP before 2.5.9 and before 3.0.0-M3.
Likely exposure
Exposure is most likely in Java applications using org.apache.opennlp:opennlp-tools that load stop-word, domain, or other dictionary files from users, tenants, partners, or external storage. Static, internally controlled dictionaries reduce practical exposure.
Exploitation context
The bundle does not cite active exploitation, and KEV is false. Practical exploitation requires influence over dictionary XML consumed by the documented Dictionary(InputStream) path or DictionaryEntryPersistor.create.
Researcher notes
The key differentiator is this parser path not using the project’s safer XmlUtil.createSaxParser helper. Focus validation on reachability of Dictionary(InputStream), trust boundaries around dictionary sources, and fixed-version confirmation. Evidence is incomplete on real-world exploitation.
Mitigation direction
- Upgrade OpenNLP 2.x deployments to 2.5.9.
- Upgrade OpenNLP 3.x deployments to 3.0.0-M3.
- Accept dictionary files only from trusted, controlled sources.
- Reject dictionary XML containing DOCTYPE before parser invocation.
- Check Apache and distribution vendor guidance for packaged fixes.
Validation and detection
- Inventory org.apache.opennlp:opennlp-tools versions, including transitive dependencies.
- Identify code paths using Dictionary(InputStream) or DictionaryEntryPersistor.create.
- Review whether dictionary files can be user, tenant, partner, or externally supplied.
- Confirm mitigated code rejects DOCTYPE-bearing dictionary XML safely.
- Verify production deployments run fixed OpenNLP versions.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CWE-611: Exact CWE lookup
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Open ATT&CK lookupCloud metadata behavior lookup
The CVE wording references SSRF or metadata access, so cloud discovery and credential material review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-40682 mapping review
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Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N3.95.2CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N3.93.6redhat-SADPVulnerability scoring details
Base CVSS 3.1 score
9.1CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- ADP timelineredhat-SADP
Made public.
- CVE publishedCVE Program
The CVE record was published.
- ADP timelineredhat-SADP
Reported to Red Hat.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2026-05-04T19:01:14.287Z: Reported to Red Hat.
- 2026-05-04T16:55:55.834Z: Made public.
Source materials
- CVE List V5 sourceCVE List V5
- https://lists.apache.org/thread/r6jpt0qr9nj67gqhppqg7jxf8vsbo0w6CVE reference, apache · vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-40682CVE reference, redhat-SADP · vdb-entry, x_refsource_REDHAT
- RHBZ#2466484CVE reference, redhat-SADP · issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40682.jsonCVE reference, redhat-SADP · x_sadp-csaf-vex
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Restriction of XML External Entity Reference
Improper Restriction of XML External Entity Reference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.