# CVE-2026-15803: XML external entity in Eclipse RDF4J

> Attackers can exploit XML External Entity vulnerabilities in Eclipse RDF4J to read sensitive files or cause denial of service via untrusted XML input.

- **Severity:** High 8.7 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Aug 2026
- **Updated:** 13 Aug 2026
- **Also known as:** GHSA-jwq9-92hc-xq2j

## What is CVE-2026-15803?

CVE-2026-15803 is a high-severity vulnerability in Eclipse RDF4J, published on 12 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-827 (Improper Control of Document Type Definition), CWE-611 (Improper Restriction of XML External Entity Reference)

## Which versions are affected by CVE-2026-15803?


## How do I fix CVE-2026-15803?

No fix has been published for CVE-2026-15803 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-15803 being exploited?

There is no known exploitation of CVE-2026-15803 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-15803 and fix it if it is affected.

What it is: CVE-2026-15803 is a high-severity vulnerability in Eclipse RDF4J, published on 12 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-15803 in the wild and no public exploit code.

Affected product: Eclipse RDF4J. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-15803/ (Markdown: https://insights.sbomify.com/CVE-2026-15803/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-15803
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-15803
- OSV: https://osv.dev/vulnerability/CVE-2026-15803

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-15803/
Summaries are generated and may contain mistakes; the official description above is the record.