CVE-2025-58187 identifies a vulnerability in the Go programming language's standard library, specifically within the crypto/x509 package responsible for certificate validation. The issue stems from the design of the name constraint checking algorithm, which exhibits inefficient algorithmic complexity. As a result, the processing time increases non-linearly relative to the size of the certificate being validated. This inefficiency can be exploited by an attacker to craft specially designed certificate chains that cause excessive CPU consumption during validation, leading to denial-of-service (DoS) conditions. The vulnerability affects all Go versions from the initial release up to 1.25.0. Because the crypto/x509 package is widely used for TLS certificate validation in many Go-based applications and services, this flaw can impact a broad range of software relying on Go for secure communications. No public exploits have been reported yet, but the potential for DoS attacks exists, especially in environments that accept arbitrary certificate chains or untrusted certificates. The vulnerability is classified under CWE-407 (Improper Control of Resource Consumption), highlighting the risk of resource exhaustion. The lack of a CVSS score requires an assessment based on the nature of the flaw, which indicates a high severity due to its impact on availability and ease of exploitation without authentication or user interaction.

For European organizations, the primary impact of CVE-2025-58187 is the risk of denial-of-service attacks targeting services that perform certificate validation using the Go crypto/x509 package. This can lead to service outages, degraded performance, and potential disruption of secure communications. Industries such as finance, telecommunications, government, and critical infrastructure that rely on Go-based applications for TLS termination or certificate chain validation are particularly at risk. The vulnerability could be exploited remotely by submitting malicious certificate chains, causing excessive CPU usage and potentially exhausting system resources. This may also affect cloud services and containerized environments where Go is commonly used. The impact extends to any system that processes untrusted certificates or performs dynamic certificate validation, increasing the attack surface. Additionally, the non-linear scaling of processing time could complicate incident response and forensic analysis due to unpredictable resource consumption patterns.

1. Monitor official Go project channels for patches addressing CVE-2025-58187 and plan immediate updates to versions beyond 1.25.0 once available. 2. Until patches are released, implement strict input validation to restrict the size and complexity of certificate chains accepted by applications. 3. Employ resource usage limits such as CPU time quotas or process timeouts on certificate validation routines to prevent excessive resource consumption. 4. Use application-layer rate limiting to reduce the risk of mass certificate validation attempts from untrusted sources. 5. Where feasible, offload certificate validation to dedicated services or hardware security modules that can better handle resource-intensive operations. 6. Conduct code audits and testing to identify any custom certificate validation logic that might be affected and refactor to avoid inefficient algorithms. 7. Enhance logging and monitoring around certificate validation processes to detect anomalies indicative of exploitation attempts. 8. Educate developers and security teams about the vulnerability to ensure rapid response and mitigation integration.