# GeoServer has a Reflected Cross-Site Scripting (XSS) vulnerability in its WMS GetFeatureInfo HTML format

Advisory record · `GHSA-w66h-j855-qr72`

- **Identifiers:** `GHSA-w66h-j855-qr72` · `CVE-2025-21621`
- **State:** Confirmed
- **Severity:** CVSS 6.1 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-79](https://cwe.mitre.org/data/definitions/79.html)
- **Tags:** [Cross-site scripting (XSS)](https://agentprime.io/advisories/tag/xss.md)
- **Published:** 25 Nov 2025
- **Updated:** 27 Nov 2025
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 25 Nov 2025, 18:41 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `org.geoserver.web:gs-web-app` (Maven): affected `<2.25.0`; fixed in `2.25.0`
- `org.geoserver:gs-wms` (Maven): affected `<2.25.0`; fixed in `2.25.0`

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 6.1 Medium, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0032, the 24th percentile, on 12 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 15:09 UTC: First seen by agentprime
- 31 Oct 2026, 15:09 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-w66h-j855-qr72)

## Sources

- [GitHub Advisory Database: GHSA-w66h-j855-qr72](https://github.com/advisories/GHSA-w66h-j855-qr72)
- [OSV: GHSA-w66h-j855-qr72](https://osv.dev/vulnerability/GHSA-w66h-j855-qr72)
- <https://github.com/geoserver/geoserver/security/advisories/GHSA-w66h-j855-qr72>
- <https://nvd.nist.gov/vuln/detail/CVE-2025-21621>
- <https://github.com/geoserver/geoserver/pull/7406>
- <https://github.com/geoserver/geoserver/commit/dc9ff1c726dd73c884437a123b4ad72b19383c7d>
- <https://github.com/geoserver/geoserver>
- <https://osgeo-org.atlassian.net/browse/GEOS-11203>
- <https://osgeo-org.atlassian.net/browse/GEOS-11297>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-w66h-j855-qr72>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-w66h-j855-qr72/>. Everything for agents: <https://agentprime.io/llms.txt>.