CVE-2026-127031Eclipse AAS Model for Java (Eclipse AAS4J) vulnerability
CVE-2026-127031 is a vulnerability in Eclipse AAS Model for Java (Eclipse AAS4J), rated high (7.7 on CVSS 4.0).
Why this priority: High severity, with no exploitation signal yet.
Published · Updated · NVD status: Received
What it is
The record does not classify the weakness yet; the description below says what the reporter found.
How it is reached
An attacker can exploit it over the network, without an account, and nobody has to click anything.
What an attacker gains
The scored direct impact on the component itself is low. The damage can spread past the vulnerable component into others.
Is it being exploited?
There is no public report of exploitation yet.
What to do
- Upgrade Eclipse AAS Model for Java (Eclipse AAS4J) to 3.0.1 or later.
- Until it is patched, keep it off the internet or behind a VPN, allowlist or authenticating proxy.
Description from NVD
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.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- Eclipse AAS Model for Java (Eclipse AAS4J). Start from where it runs and what it is connected to.
Trust boundaries in play
- Internet-facing entry points. No account is needed. Any instance reachable from outside your perimeter, through a load balancer, gateway, VPN or exposed admin port, is in scope.
- Isolation between components. The impact crosses out of the vulnerable component into others it should be isolated from.
Questions to answer about your own systems
- Where does Eclipse AAS Model for Java (Eclipse AAS4J) run in your systems, and at which version?
- Which of those instances can be reached from the internet or partner networks?
- What can it reach once compromised: which data stores, secrets and services?
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.