---
id: "CVE-2026-108086"
kind: "vulnerability"
aliases: ["CVE-2026-108086"]
title: "Apache Cocoon: XML entity expansion in form processor enables server-side request forgery"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["apache-cocoon", "java", "package", "self-hosted"]
not_affected_if: ["auth-required", "not-using-cocoon"]
published_at: "2026-10-20T11:17:16+00:00"
first_seen_at: "2026-10-23T21:57:20+00:00"
updated_at: "2026-10-25T05:04:54+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-108086", "first_seen_at": "2026-10-23T21:57:20+00:00"}]
---

# Apache Cocoon: XML entity expansion in form processor enables server-side request forgery

Apache Cocoon's fp: form processor does not restrict recursive entity references in XML DTDs, an XML entity expansion flaw. An attacker can use it to make the server fetch internal or external resources and expose server files to an outside system.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check whether Apache Cocoon is deployed and which version is in use, for example by looking for `cocoon` JARs in the application's classpath or lib directory.
- Check whether the `fp:` form processor is used in any Cocoon sitemap or pipeline.

## Fix

- No fix is planned: the project is retired and the maintainer will not release a patched version.
- Move to an alternative framework, or restrict access to the instance to trusted users only.

## Timeline

- 2026-10-23T21:57:20+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-108086

## From the sources

** UNSUPPORTED WHEN ASSIGNED ** Improper restriction of recursive entity references in DTDs ('XML entity expansion') vulnerability in Apache Cocoon.



This issue affects Apache Cocoon: all versions. XEE in the fp: form processor could lead to SSRF, including exposing files from the server to an untrusted external system



As this project is retired, we do not plan to release a version that fixes this issue. Users are recommended to find an alternative or restrict access to the instance to trusted users.



NOTE: This vulnerability only affects products that are no longer supported by the maintainer.

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