# CVE-2026-55864: GeoNetwork: Unauthenticaded Server-Side Request Forgery in SLD Tool

> An anonymous attacker can exploit an SSRF vulnerability in the SLD tool to access internal network resources and disclose sensitive data.

- **Severity:** High 7.8 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Sep 2026
- **Updated:** 16 Sep 2026
- **Also known as:** GHSA-5hx7-j24v-rffj

## What is CVE-2026-55864?

CVE-2026-55864 is a high-severity server-side request forgery vulnerability in core-geonetwork, published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

GeoNetwork is a catalog application to manage spatially referenced resources. Prior to 4.2.17 and 4.4.12, POST /api/tools/ogc/sld accepted a caller-supplied WMS server URL and performed a server-side HTTP GET without destination validation. An anonymous attacker could make the GeoNetwork server send requests to internal hosts that are not publicly reachable. When the outbound response was XML, the endpoint could store and return the fetched body, making the request forgery non-blind and enabling internal data disclosure, authorization bypass, and network reconnaissance. This issue is fixed in versions 4.2.17 and 4.4.12.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-55864?

4 open source packages ship an affected version, including org.geonetwork-opensource:gn-web-app.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.geonetwork-opensource:gn-web-app` | Maven | From 4.0.0 | 4.2.17 |
| `org.geonetwork-opensource:gn-web-app` | Maven | From 4.0.0 | 4.2.17 |
| `org.geonetwork-opensource:gn-web-app` | Maven | From 4.4.0 | 4.4.12 |
| `org.geonetwork-opensource:gn-web-app` | Maven | From 4.4.0 | 4.4.12 |

## How do I fix CVE-2026-55864?

Upgrade org.geonetwork-opensource:gn-web-app to a fixed version for your release line: 4.2.17 or 4.4.12.

## Is CVE-2026-55864 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55864 exists.

Public exploit code:

- GeoNetwork - Server-Side Request Forgery (SSRF) (nuclei): http/cves/2026/CVE-2026-55864.yaml

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55864 and fix it if it is affected.

What it is: CVE-2026-55864 is a high-severity server-side request forgery vulnerability in core-geonetwork, published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55864 exists.

Affected packages and fixed versions:
- org.geonetwork-opensource:gn-web-app (Maven): affected from 4.0.0; fixed in 4.2.17
- org.geonetwork-opensource:gn-web-app (Maven): affected from 4.0.0; fixed in 4.2.17
- org.geonetwork-opensource:gn-web-app (Maven): affected from 4.4.0; fixed in 4.4.12
- org.geonetwork-opensource:gn-web-app (Maven): affected from 4.4.0; fixed in 4.4.12

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-2026-55864/ (Markdown: https://insights.sbomify.com/CVE-2026-55864/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55864
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55864
- OSV: https://osv.dev/vulnerability/CVE-2026-55864

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-55864/
Summaries are generated and may contain mistakes; the official description above is the record.