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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| 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 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Maven | org.geoserver:gs-main | < 2.26.4 | 2.26.4 | GHSA-x4r9-gmw3-hxww |
| Maven | org.geoserver:gs-main | >= 2.27.0, < 2.27.3 | 2.27.3 | GHSA-x4r9-gmw3-hxww |
| Maven | org.geoserver.web:gs-web-app | < 2.26.4 | 2.26.4 | GHSA-x4r9-gmw3-hxww |
| Maven | org.geoserver.web:gs-web-app | >= 2.27.0, < 2.27.3 | 2.27.3 | GHSA-x4r9-gmw3-hxww |
Advisories 1
- WID-SEC-2026-1902 GeoServer: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jun 18, 2026