How severe is CVE-2023-41034?

CVE-2023-41034 has a CVSS score of 6.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2023-41034?

CVE-2023-41034 affects the following packages: org.eclipse.leshan:leshan-core (Maven), org.eclipse.leshan:leshan-core (Maven). Ecosystems affected: Maven.

How do I fix CVE-2023-41034?

Update org.eclipse.leshan:leshan-core to 1.5.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-41034 is resolved across your whole dependency graph.

How do I detect CVE-2023-41034 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.eclipse.leshan:leshan-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2023-41034 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2023-41034 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-41034 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-41034?

CVE-2023-41034 has an EPSS (Exploit Prediction Scoring System) score of 0.7%, placing it in the 53th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2023-41034?

CVE-2023-41034 is classified as XML External Entity (XXE) (CWE-611). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2023-41034 published, and has it been updated?

CVE-2023-41034 was published on August 31, 2023 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

Not in CISA KEV

MEDIUM severity

CVE-2023-41034 — leshan-core

MEDIUMFix: eclipse-leshan/leshan@29577d2

CVE-2023-41034 is a medium-severity (CVSS 6.5) XML External Entity (XXE) vulnerability in org.eclipse.leshan:leshan-core. A fix is available for org.eclipse.leshan:leshan-core — see the affected versions and patch details below.

DDFFileParser in eclipse leshan is vulnerable to XXE Attacks

Also known asGHSA-wc9j-gc65-3cm7

Published

Aug 31, 2023

Updated

Oct 28, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2023-41034.

EPSS Exploitation Probability

via FIRST.org ↗

0.7%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs53th percentile — riskier than 53% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected

☕org.eclipse.leshan:leshan-core☕org.eclipse.leshan:leshan-core

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Impact

DDFFileParser and DefaultDDFFileValidator (and so ObjectLoader) are vulnerable to XXE Attacks.

DDF file is a LWM2M format used to store LWM2M object description.
Leshan users are impacted only if they parse untrusted DDF files (e.g. if they let external users provide their own model), in that case they MUST upgrade to fixed version. If you parse only trusted DDF file and validate only with trusted xml schema, upgrading is not mandatory.

Patches

This is fixed in v1.5.0 and 2.0.0-M13.

Workarounds

No easy way. Eventually writing your own DDFFileParser/DefaultDDFFileValidator (and so ObjectLoader) creating a DocumentBuilderFactory with :

// For DDFFileParser
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);
factory.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true); // Disable DTDs
factory.setXIncludeAware(false); // Disable XML Inclusions
factory.setExpandEntityReferences(false); // disable expand entity reference nodes

// For DefaultDDFFileValidator
SchemaFactory factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
factory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);
factory.setProperty(XMLConstants.ACCESS_EXTERNAL_DTD, "");
factory.setProperty(XMLConstants.ACCESS_EXTERNAL_SCHEMA, "");

References

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.eclipse.leshan:leshan-core`	all versions	1.5.0`org.eclipse.leshan:leshan-core:1.5.0`
☕Maven	`org.eclipse.leshan:leshan-core`	≥ 2.0.0-M1&&< 2.0.0-M13	2.0.0-M13`org.eclipse.leshan:leshan-core:2.0.0-M13`

Affected Products

1 product · 13 configurations

Application

leshaneclipse

< 1.5.0

1 version

2.0.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.eclipse.leshan:leshan-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.eclipse.leshan:leshan-core to 1.5.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-41034 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

### Impact `DDFFileParser` and `DefaultDDFFileValidator` (and so `ObjectLoader`) are vulnerable to [XXE Attacks](https://owasp.org/www-community/vulnerabilities/XML_External_Entity_(XXE)_Processing). [DDF file](https://github.com/eclipse-leshan/leshan/wiki/Adding-new-objects#the-lwm2m-model) is a LWM2M format used to store LWM2M object description. Leshan users are impacted only if they parse untrusted DDF files (e.g. if they let external users provide their own model), in that case they MUST upgrade to fixed version. If you parse only trusted DDF file and validate only with trusted xml sc