GHSA-x4r9-gmw3-hxww is a medium-severity (CVSS 6.5) Improper Input Validation vulnerability in org.geoserver.web:gs-web-app. O3 Security confirms whether GHSA-x4r9-gmw3-hxww is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
GeoServer has a Server-Side Request Forgery (SSRF) Vulnerability in its XML Entity Resolution
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-x4r9-gmw3-hxww.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-x4r9-gmw3-hxww plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 0 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
org.geoserver.web:gs-web-app☕org.geoserver:gs-main☕org.geoserver:gs-main☕org.geoserver.web:gs-web-appReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Summary
A GeoServer that uses ENTITY_RESOLUTION_ALLOWLIST may allow attacker to perform unauthenticated Server-Side Request Forgery (SSRF).
Details
This vulnerability requires that GeoServer is set up to use a proxy base URL and the ENTITY_RESOLUTION_ALLOWLIST (default since 2.25.0):
Impact
This vulnerability allows an attacker to cause GeoServer to make requests to an unintended location.
Workaround
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 (e.g., https://somesite.org instead of https://somesite.org/ or https://somesite.org/geoserver). If the proxy base URL does not contain a path, adding a slash to the end of the URL will mitigate this vulnerability.
Resources
https://osgeo-org.atlassian.net/browse/GEOS-11867 https://github.com/geoserver/geoserver/pull/8622
Credits:
- Le Mau Anh Phong at Verichains Cyber Force
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.geoserver.web:gs-web-app | all versions | 2.26.4 |
| ☕Maven | org.geoserver:gs-main | all versions | 2.26.4 |
| ☕Maven | org.geoserver:gs-main | ≥ 2.27.0&&< 2.27.3 | 2.27.3 |
| ☕Maven | org.geoserver.web:gs-web-app | ≥ 2.27.0&&< 2.27.3 | 2.27.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.geoserver.web:gs-web-app. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update org.geoserver.web:gs-web-app to 2.26.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-x4r9-gmw3-hxww is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-x4r9-gmw3-hxww is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-x4r9-gmw3-hxww. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-x4r9-gmw3-hxww in your dependencies?
O3 detects GHSA-x4r9-gmw3-hxww across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.