CVE-2025-47952 is a path traversal vulnerability identified in Traefik, a widely used HTTP reverse proxy and load balancer. This vulnerability affects versions prior to 2.11.25 and 3.4.1. Traefik uses matchers such as PathPrefix, Path, or PathRegex to route incoming HTTP requests to backend services. The flaw arises when Traefik processes URL paths containing URL-encoded strings. An attacker can craft a specially encoded URL path that bypasses the intended routing logic and middleware protections, enabling access to backend services exposed through other routers. This effectively allows an attacker to circumvent security controls implemented via middleware chains, potentially exposing sensitive backend endpoints that should be protected or isolated. The vulnerability is classified under CWE-22, which relates to improper limitation of a pathname to a restricted directory, commonly known as path traversal. Although the CVSS v4.0 score is low (2.9), reflecting limited impact and exploitation complexity, the issue could lead to unauthorized access to backend services if exploited. The vulnerability does not require authentication or user interaction but does require network access to the Traefik instance. No known exploits are currently reported in the wild, and the issue has been patched in Traefik versions 2.11.25 and 3.4.1. Organizations using affected Traefik versions should prioritize upgrading to these patched releases to mitigate the risk.

For European organizations, the impact of this vulnerability depends on the deployment of Traefik in their infrastructure. Traefik is popular in cloud-native environments and microservices architectures, which are common in European enterprises and public sector organizations. Exploitation could allow attackers to bypass middleware protections, potentially exposing internal backend services that may contain sensitive data or critical business logic. This could lead to unauthorized data access, information disclosure, or lateral movement within the network. While the CVSS score is low, the ability to bypass middleware chains can undermine layered security controls, increasing the risk of further exploitation. Organizations in sectors such as finance, healthcare, and government, which often use reverse proxies for service segmentation and security, may face increased risk if they have not updated Traefik. Additionally, given the European Union's strict data protection regulations (e.g., GDPR), any unauthorized data exposure could result in regulatory penalties and reputational damage.

1. Immediate upgrade of Traefik to versions 2.11.25 or 3.4.1 or later to apply the official patch addressing this vulnerability. 2. Review and audit Traefik routing configurations, especially those using PathPrefix, Path, or PathRegex matchers, to ensure no unintended backend exposure exists. 3. Implement strict input validation and normalization on URL paths at the application or proxy level to detect and block suspicious URL-encoded sequences that could be used for traversal. 4. Employ network segmentation and zero-trust principles to limit backend service exposure, ensuring that even if routing is bypassed, access to sensitive services is controlled. 5. Monitor Traefik logs for unusual or malformed URL requests that may indicate attempted exploitation. 6. Use Web Application Firewalls (WAFs) or API gateways with rules to detect and block path traversal attempts. 7. Conduct penetration testing focused on proxy routing logic to identify any residual or related vulnerabilities.