CVE-2026-2653 identifies a heap-based buffer overflow vulnerability in the open-source software admesh, versions 0.98.0 through 0.98.5. The flaw resides in the stl_check_normal_vector function located in src/normals.c, which processes STL file normal vectors. Improper handling or manipulation of input data in this function leads to a heap buffer overflow, causing memory corruption. This vulnerability requires an attacker to have local access with low privileges, as the attack vector is local and no user interaction is necessary. The overflow could potentially allow an attacker to execute arbitrary code or cause a denial of service by crashing the application. The exploit code has been publicly released, increasing the risk of exploitation. However, the product is reportedly no longer maintained, and no official patches or updates are available to remediate the issue. The CVSS v4.0 score is 4.8 (medium severity), reflecting the limited attack vector and privileges required. The vulnerability impacts confidentiality, integrity, and availability to a limited extent due to the local access requirement and lack of network-based exploitation. Admesh is commonly used in 3D model processing and CAD workflows, particularly for STL files, which are prevalent in manufacturing and prototyping environments.

For European organizations, the primary impact lies in environments where admesh is used for 3D model processing, such as manufacturing, engineering, and prototyping sectors. Exploitation could lead to unauthorized code execution or application crashes, potentially disrupting critical design or manufacturing workflows. Although remote exploitation is not feasible, insider threats or compromised local accounts could leverage this vulnerability to escalate privileges or disrupt operations. The lack of maintenance and absence of patches increase the risk of prolonged exposure. Disruptions could affect production timelines and intellectual property confidentiality if exploited. Given the niche usage of admesh, the overall impact is moderate but could be significant in organizations relying heavily on this tool for STL file validation and processing.

Since no official patches are available due to the product's unmaintained status, European organizations should consider the following mitigations: 1) Restrict local access to systems running admesh to trusted personnel only, enforcing strict access controls and monitoring. 2) Employ application sandboxing or containerization to limit the impact of potential exploitation. 3) Replace admesh with actively maintained and patched alternatives for STL processing where feasible. 4) Implement host-based intrusion detection systems (HIDS) to detect anomalous behavior indicative of exploitation attempts. 5) Conduct regular audits of systems using admesh to identify and isolate vulnerable instances. 6) Educate local users about the risks of executing untrusted STL files or software components. 7) If continued use is necessary, consider code review or custom patching by internal security teams to mitigate the overflow. These steps go beyond generic advice by focusing on containment, replacement, and proactive monitoring tailored to the local attack vector and product status.