GeoServer - Authentication Bypass (CVE-2025-27505)

CVE-2025-27505 is a security vulnerability in GeoServer that allows attackers to bypass REST API security controls by accessing the API index page with certain file extensions, such as .html. This flaw can expose information about installed extensions, potentially aiding reconnaissance and further attacks. The issue is resolved in versions 2.26.3 and 2.25.6.

CrowdSec has been tracking this vulnerability and its exploits since 16th of July 2025.

Data from the CrowdSec community indicates that exploitation of CVE-2025-27505 is highly selective and intelligence-driven. Threat actors use advanced reconnaissance and carefully choose their targets, often as part of sophisticated campaigns or advanced persistent threat operations. Telemetry from the CrowdSec network also shows that exploitation activity for CVE-2025-27505 remains steady week-over-week. Attack volumes are consistent with long-term trends, indicating sustained interest from threat actors. CVE-2025-27505 continues to be an active part of the threat landscape and will likely remain this way for the forseeable future.

Attackers exploit this vulnerability by directly accessing the /rest.html or /geoserver/rest.html endpoints, exposing sensitive GeoServer configuration information without proper authorization.