What is the CVSS score of CVE-2025-21621?

CVE-2025-21621 has a CVSS 3.1 base score of 6.1 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N. EPSS exploitation probability: 0.1%.

Which versions of Geoserver are affected by CVE-2025-21621?

Organizations using GeoServer should be aware of moderate risk from CVE-2025-21621, a cross-site scripting vulnerability rated CVSS 6.1.. A patch is available.

How to fix or mitigate CVE-2025-21621?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Verify Content-Security-Policy and output encoding.

Geoserver CVE-2025-21621

MEDIUM

Cross-site Scripting (XSS) (CWE-79)

2025-11-25 security-advisories@github.com

XSS Geoserver

6.1

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

6.1 MEDIUM

AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Analysis Generated

Mar 28, 2026 - 19:23 vuln.today

Patch released

Mar 28, 2026 - 19:23 nvd

Patch available

CVE Published

Nov 25, 2025 - 22:15 nvd

MEDIUM 6.1

DescriptionGitHub Advisory

GeoServer is an open source server that allows users to share and edit geospatial data. Prior to version 2.25.0, 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. This issue has been patched in version 2.25.0.

AnalysisAI

GeoServer is an open source server that allows users to share and edit geospatial data. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.

Technical ContextAI

This vulnerability is classified as Cross-Site Scripting (XSS) (CWE-79), which allows attackers to inject malicious scripts into web pages viewed by other users. GeoServer is an open source server that allows users to share and edit geospatial data. Prior to version 2.25.0, 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. This issue has been patched in version 2.25.0. Affected products include: Geoserver. Version information: version 2.25.0.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Sanitize all user input, use Content-Security-Policy headers, encode output contextually (HTML, JS, URL). Use frameworks with built-in XSS protection.