CVE-2026-127031
Received
Received - Intake
XML External Entity Injection in Eclipse AAS4J
Vulnerability report for CVE-2026-127031, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-11-13
Last updated on: 2026-11-13
Assigner: Eclipse Foundation
Description
Description
In Eclipse AAS4J before 3.0.1, `XmlSchemaValidator.validateSchema()` (and `AASXValidator.validateSchema()`, which calls it) validates untrusted XML with a default JAXP `Validator` that resolves external DTDs and external entities. An attacker who supplies a crafted AAS XML document or AASX package can read local files from the host, send their contents out-of-band to an attacker-controlled server, and make the validating process send arbitrary outbound requests (SSRF). Validation still returns no errors.
Details:
- Vulnerable code: `dataformat-xml/src/main/java/org/eclipse/digitaltwin/aas4j/v3/dataformat/xml/XmlSchemaValidator.java`. `schema.newValidator().validate(new StreamSource(...))` runs without `ACCESS_EXTERNAL_DTD` / `ACCESS_EXTERNAL_SCHEMA` restrictions and without `disallow-doctype-decl`.
- Second entry point: `dataformat-aasx/src/main/java/org/eclipse/digitaltwin/aas4j/v3/dataformat/aasx/AASXValidator.java`. The AAS XML part of an `.aasx` package is passed unchanged to the vulnerable validator.
- `XmlDeserializer` (Jackson/Woodstox) is not affected, because DTD support is disabled by default there.
- Present since the initial import of the code base (commit `cc9da52`).
- Fix: harden the validator by setting `ACCESS_EXTERNAL_DTD` and `ACCESS_EXTERNAL_SCHEMA` to `""` and rejecting `DOCTYPE` declarations. The bundled `AAS.xsd` does not need DTDs, so no functionality is lost.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| Eclipse Foundation | Eclipse AAS Model for Java (Eclipse AAS4J) | From 0 (inc) to 3.0.1 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
