CVE-2025-15564 is a vulnerability identified in Mapnik, an open-source toolkit widely used for rendering maps and geospatial data. The flaw exists in the function mapnik::detail::mod<...>::operator located in src/value.cpp, where improper handling of input leads to a divide-by-zero error. This error can cause the Mapnik process to crash, resulting in a denial of service (DoS) condition. The vulnerability affects Mapnik versions 4.0, 4.1, and 4.2.0. Exploitation requires local access with low privileges, meaning an attacker must have some form of local system access to trigger the fault. No user interaction is needed once local access is obtained. The vulnerability does not appear to allow code execution, privilege escalation, or data leakage, but it can disrupt availability by crashing services relying on Mapnik. The vulnerability was responsibly disclosed early to the Mapnik project, but no patch has been released at the time of publication. The CVSS 4.0 vector indicates low attack complexity and no user interaction, with a medium overall severity score of 4.8. No known exploits are currently observed in the wild, but public disclosure increases the risk of exploitation attempts. Organizations using Mapnik in their geospatial infrastructure should monitor for crashes and prepare mitigation strategies.

The primary impact of CVE-2025-15564 is denial of service due to application crashes caused by the divide-by-zero error. For European organizations relying on Mapnik for critical geospatial rendering, mapping services, or location-based analytics, this could lead to service interruptions, affecting operational continuity and user experience. While the vulnerability does not compromise data confidentiality or integrity, availability disruptions can impact sectors such as transportation, urban planning, emergency response, and utilities that depend on accurate and timely geospatial data. The requirement for local access limits the attack surface, reducing the likelihood of remote exploitation. However, insider threats or compromised local accounts could exploit this vulnerability. The absence of a patch means organizations must rely on compensating controls until a fix is available. The medium severity rating reflects these factors, indicating moderate risk primarily to service availability.

1. Restrict local access to systems running vulnerable Mapnik versions by enforcing strict user permissions and access controls. 2. Monitor Mapnik service logs and system stability to detect crashes or abnormal behavior indicative of exploitation attempts. 3. Employ host-based intrusion detection systems (HIDS) to alert on unusual local activity targeting Mapnik processes. 4. Isolate Mapnik services in containerized or sandboxed environments to limit the impact of crashes on broader system stability. 5. Regularly review and update system user accounts to minimize the number of users with local access privileges. 6. Engage with the Mapnik project or community to track patch releases and apply updates promptly once available. 7. Consider implementing application-level input validation or runtime checks if feasible to prevent triggering the divide-by-zero condition. 8. Develop incident response plans specifically addressing potential denial of service scenarios affecting geospatial services.