Description
GeoServer is an open source server that allows users to share and edit geospatial data. Prior to versions 2.26.4 and 2.27.3, a GeoServer that uses `ENTITY_RESOLUTION_ALLOWLIST` may allow attacker to perform unauthenticated Server-Side Request Forgery (SSRF). This vulnerability requires that GeoServer is set up to use a proxy base URL and the `ENTITY_RESOLUTION_ALLOWLIST` (default since 2.25.0). Versions 2.26.4 and 2.27.3 contain a fix. GeoServer installations are only affected by this vulnerability if they use a proxy base URL that does not contain a URL path or end with a slash. If the proxy base URL does not contain a path, adding a slash to the end of the URL will mitigate this vulnerability.
Metrics
CVSS 3.1 8.2/10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:LWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| geoserver | org.geoserver.web:gs-web-app | < 2.26.4; >= 2.27.0, < 2.27.3 |
| geoserver | org.geoserver:gs-main | < 2.26.4; >= 2.27.0, < 2.27.3 |
References
- https://github.com/geoserver/geoserver/pull/8622Issue Tracking, Patch
- https://github.com/geoserver/geoserver/security/advisories/GHSA-x4r9-gmw3-hxwwMitigation, Vendor Advisory
- https://osgeo-org.atlassian.net/browse/GEOS-11867Issue Tracking
Timeline
- Published
- Jun 18, 2026
- Last modified
- Oct 6, 2026
- NVD status
- Analyzed