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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS

• CVE-2025-21621: 0.32% estimated exploitation activity in the next 30 days; percentile 24.70 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary A reflected cross-site scripting (XSS) vulnerability exists in the WMS GetFeatureInfo HTML output format that enables a remote attacker to execute arbitrary JavaScript code in a victim's browser through specially crafted SLDBODY parameters. Details The WMS service setting that controls HTML auto-escaping is either disabled by default, or completely missing, in the affected versions (see workarounds). Impact If an attacker can control a script that is executed in the victim's browser, then they can typically fully compromise that user. Amongst other things, the attacker can: 1. Perform any action within the application that the user can perform. 2. View any information that the user is able to view. 3. Modify any information that the user is able to modify. 4. Initiate interactions with other application users, including malicious attacks, that will appear to originate from the initial victim user. Workarounds Changing any of the following WMS service settings should mitigate…

Published by the source

25 Nov 2025, 18:41 UTC

Last modified by the source

27 Nov 2025, 09:00 UTC

Source last checked

26 Oct 2026, 16:41 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-w66h-j855-qr72

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# Patch Next advisory brief: CVE-2025-21621

Advisory: GeoServer has a Reflected Cross-Site Scripting (XSS) vulnerability in its WMS GetFeatureInfo HTML format
IDs: CVE-2025-21621, GHSA-w66h-j855-qr72
Record: https://patchnext.com/advisories/cve-2025-21621 (revision 1, source checked 26 Oct 2026, 16:41 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.geoserver.web:gs-web-app 2.25.0; org.geoserver:gs-wms 2.25.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.geoserver.web:gs-web-app: affected < 2.25.0; fixed in 2.25.0
- Maven org.geoserver:gs-wms: affected < 2.25.0; fixed in 2.25.0

## Suggested inspection (read-only)
- Maven org.geoserver.web:gs-web-app: check the installed version with your package manager.
- Maven org.geoserver:gs-wms: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.geoserver.web:gs-web-app, org.geoserver:gs-wms.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-w66h-j855-qr72 (GitHub-reviewed advisory GHSA-w66h-j855-qr72 lists affected ranges: Maven org.geoserver.web:gs-web-app >=0 =0 <2.25.0)

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