6.1
Medium
org.geoserver.web:gs-web-app

CVE-2025-21621

CVE-2025-21621 is a medium-severity cross-site scripting (XSS) vulnerability in org.geoserver.web:gs-web-app (maven), affecting versions < 2.25.0. It is fixed in 2.25.0.

Key facts
CVSS score
6.1
Medium
Attack vector
Network
Issuing authority
GitHub Advisory Database
Affected package
org.geoserver.web:gs-web-app
Fixed in
2.25.0
Disclosed
2025

Summary

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 SLD_BODY 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: Perform any action within the application that the user can perform. View any information that the user is able to view. Modify any information that the user is able to modify. 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 this vulnerability in most environments: Enable GetFeatureInfo HTML auto-escaping (available in GeoServer 2.21.3+ and 2.22.1+) Disable dynamic styling Disable GetFeatureInfo text/html MIME type References https://osgeo-org.atlassian.net/browse/GEOS-11297 https://github.com/geoserver/geoserver/pull/7406

Impact

What is cross-site scripting (XSS)?

Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.

Severity and exposure

CVE-2025-21621 has a CVSS score of 6.1 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.

A fixed version is available (2.25.0). Upgrading removes the vulnerable code path.

Affected versions

maven

  • org.geoserver.web:gs-web-app (< 2.25.0)
  • org.geoserver:gs-wms (< 2.25.0)

Security releases

  • org.geoserver.web:gs-web-app → 2.25.0 (maven)
  • org.geoserver:gs-wms → 2.25.0 (maven)
Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.

Kodem's runtime-powered SCA identifies whether CVE-2025-21621 is reachable in your applications. Explore open-source security for your team.

See if CVE-2025-21621 is reachable in your applications. Get a demo

Remediation advice

Upgrade the following packages to resolve this vulnerability:

  • Upgrade org.geoserver.web:gs-web-app to 2.25.0 or later
  • Upgrade org.geoserver:gs-wms to 2.25.0 or later

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently asked questions about CVE-2025-21621

What is CVE-2025-21621?

CVE-2025-21621 is a medium-severity cross-site scripting (XSS) vulnerability in org.geoserver.web:gs-web-app (maven), affecting versions < 2.25.0. It is fixed in 2.25.0. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.

How severe is CVE-2025-21621?

CVE-2025-21621 has a CVSS score of 6.1 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Which packages are affected by CVE-2025-21621?
  • org.geoserver.web:gs-web-app (maven) (versions < 2.25.0)
  • org.geoserver:gs-wms (maven) (versions < 2.25.0)
Is there a fix for CVE-2025-21621?

Yes. CVE-2025-21621 is fixed in 2.25.0. Upgrade to this version or later.

Is CVE-2025-21621 exploitable, and should I be worried?

Whether CVE-2025-21621 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo

What actually determines whether CVE-2025-21621 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

How do I fix CVE-2025-21621?
  • Upgrade org.geoserver.web:gs-web-app to 2.25.0 or later
  • Upgrade org.geoserver:gs-wms to 2.25.0 or later

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