CVE-2025-61726 identifies a vulnerability in the Go programming language's standard library, specifically within the net/url package. The issue arises because the package does not impose any limit on the number of query parameters that can be parsed from a URL. Although the maximum size of query parameters is generally constrained by the maximum request header size, the net/http.Request.ParseForm method can parse very large URL-encoded forms containing numerous unique query parameters. This can lead to uncontrolled resource consumption, particularly excessive memory usage, when processing such requests. The vulnerability is classified under CWE-400 (Uncontrolled Resource Consumption), indicating that an attacker can craft a URL with an extremely large number of query parameters to cause the target server to consume excessive memory resources. This can result in denial of service (DoS) conditions by exhausting available memory, potentially crashing the application or severely degrading its performance. The vulnerability affects all Go versions from the initial release up to version 1.25.0. It can be exploited remotely over the network without requiring any authentication or user interaction, making it a significant risk for publicly accessible Go-based web services. Although no known exploits have been reported in the wild as of the publication date, the high CVSS score of 7.5 reflects the potential impact and ease of exploitation. No official patches or fixes are currently linked, so users must rely on mitigation strategies until an update is released.

For European organizations, this vulnerability poses a substantial risk to the availability and reliability of web services developed using the Go programming language. Many modern cloud-native applications, microservices, and APIs in Europe leverage Go for its performance and concurrency features. An attacker exploiting this vulnerability can cause denial of service by overwhelming the server's memory, leading to application crashes or degraded service performance. This can disrupt business operations, cause financial losses, and damage reputation. Critical sectors such as finance, healthcare, telecommunications, and government services that rely on Go-based infrastructure are particularly vulnerable. Additionally, the lack of authentication or user interaction requirements means that automated attacks or bots can easily exploit this flaw at scale. The impact is amplified in environments where input validation or request size limitations are not properly enforced. Given the increasing adoption of Go in European technology stacks, the vulnerability could affect a wide range of organizations from startups to large enterprises and public sector entities.

Until an official patch is released, European organizations should implement several practical mitigations to reduce risk. First, enforce strict limits on the number of query parameters accepted by web applications or API gateways, rejecting requests that exceed reasonable thresholds. This can be done at the application layer or via reverse proxies and web application firewalls (WAFs). Second, implement request size limits and timeout settings to prevent resource exhaustion from large or slow requests. Third, monitor application logs and metrics for unusual spikes in query parameter counts or memory usage to detect potential exploitation attempts early. Fourth, consider deploying rate limiting and IP reputation filtering to reduce exposure to automated attacks. Fifth, review and update input validation routines to sanitize and constrain incoming URL parameters. Finally, plan to upgrade to a patched version of the Go standard library as soon as it becomes available, and test applications thoroughly to ensure compatibility. Organizations should also maintain incident response readiness to quickly mitigate any denial of service events stemming from this vulnerability.