# CVE-2026-6501: jOpenDocument has an improper restriction of XML external entity reference vulnerability

> An attacker can cause a denial of service via XML external entity blowup in the jOpenDocument library.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 May 2026
- **Updated:** 4 May 2026
- **Also known as:** GHSA-j9rh-p96m-mhhp

## What is CVE-2026-6501?

CVE-2026-6501 is a medium-severity vulnerability in ILM  Informatique jOpenDocument, published on 4 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Improper restriction of XML external entity reference vulnerability in ILM Informatique jOpenDocument allows Data Serialization External Entities Blowup.

This issue affects jOpenDocument: 1.5.

Weakness: CWE-611 (Improper Restriction of XML External Entity Reference)

## Which versions are affected by CVE-2026-6501?

2 open source packages ship an affected version, including org.jopendocument:jOpenDocument.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.jopendocument:jOpenDocument` | Maven | All versions to 1.3 | None |
| `org.jopendocument:jOpenDocument` | Maven | All versions to 1.3 | None |

## How do I fix CVE-2026-6501?

No fix has been published for CVE-2026-6501 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-6501 being exploited?

There is no known exploitation of CVE-2026-6501 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-6501 and fix it if it is affected.

What it is: CVE-2026-6501 is a medium-severity vulnerability in ILM  Informatique jOpenDocument, published on 4 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-6501 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.jopendocument:jOpenDocument (Maven): affected all versions up to 1.3; no fix listed
- org.jopendocument:jOpenDocument (Maven): affected all versions up to 1.3; no fix listed

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-2026-6501/ (Markdown: https://insights.sbomify.com/CVE-2026-6501/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-6501
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-6501
- OSV: https://osv.dev/vulnerability/CVE-2026-6501

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-6501/
Summaries are generated and may contain mistakes; the official description above is the record.