CVE-2025-31177 is a heap-based buffer overflow vulnerability identified in the function utf8_copy_one within the gnuplot software. Gnuplot is a widely used command-line driven graphing utility that generates plots and graphs from data sets. The vulnerability arises when the utf8_copy_one function improperly handles memory allocation or copying operations on UTF-8 encoded data, leading to an overflow of the heap buffer. This type of vulnerability can cause the program to crash or behave unpredictably, potentially allowing an attacker to execute arbitrary code or cause a denial of service (DoS). The CVSS v3.1 score for this vulnerability is 6.2, indicating a medium severity level. The vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H indicates that the attack requires local access (AV:L), has low complexity (AC:L), requires no privileges (PR:N), no user interaction (UI:N), and impacts availability only (A:H) without affecting confidentiality or integrity. No known exploits are currently reported in the wild, and no patches or vendor advisories are linked yet. The vulnerability was reserved in March 2025 and published in May 2025, with Red Hat as the assigner. Given the nature of the vulnerability, exploitation would require local access to the system running gnuplot, and it primarily results in denial of service by crashing or destabilizing the application rather than data theft or modification.

For European organizations, the primary impact of CVE-2025-31177 is the potential disruption of services or workflows that rely on gnuplot for data visualization and graphing. Since gnuplot is often used in scientific research, engineering, and data analysis environments, a successful exploitation could cause application crashes, leading to loss of productivity and potential delays in critical data processing tasks. Although the vulnerability does not compromise confidentiality or integrity, availability impacts could affect operational continuity, especially in research institutions, universities, and industries relying on automated graph generation. The requirement for local access limits the risk from remote attackers, but insider threats or compromised internal systems could exploit this vulnerability. Additionally, automated systems or batch jobs invoking gnuplot could be disrupted, causing cascading effects in data pipelines. The absence of known exploits reduces immediate risk, but organizations should remain vigilant as exploit code could emerge over time.

To mitigate CVE-2025-31177, European organizations should first identify all instances of gnuplot in their environments, especially on systems accessible to multiple users or exposed to untrusted local users. Since no patches are currently linked, organizations should monitor vendor advisories and security mailing lists for updates or patches addressing this vulnerability. In the interim, restricting local access to trusted users only and applying strict access controls on systems running gnuplot can reduce exploitation risk. Employing application whitelisting and monitoring for abnormal crashes or behavior in gnuplot processes can help detect exploitation attempts. For critical systems, consider isolating gnuplot usage in sandboxed or containerized environments to limit the impact of potential crashes. Additionally, reviewing and sanitizing input data to gnuplot, especially UTF-8 encoded data, may reduce the chance of triggering the overflow. Finally, integrating this vulnerability into vulnerability management and incident response processes will ensure timely action once patches become available.