CVE-2025-65834 is a critical buffer overflow vulnerability identified in Meltytech Shotcut version 25.10.31, a popular open-source video editing software. The vulnerability occurs during the processing of MLT project files, specifically when the width and height parameters are maliciously manipulated to extremely large values. These parameters cause the application to attempt to allocate an excessive amount of memory during image processing within the mlt_image_fill_white function. This leads to a buffer overflow condition, classified under CWE-120 (Classic Buffer Overflow). The flaw is exploitable remotely without any authentication or user interaction, as simply opening a crafted project file can trigger the overflow. The consequences of exploitation include arbitrary code execution, complete system compromise, and denial of service due to memory corruption. The CVSS v3.1 base score is 9.8, reflecting the critical nature of this vulnerability with high impact on confidentiality, integrity, and availability. Although no public exploits are currently known, the vulnerability's characteristics make it a prime target for attackers once weaponized. The lack of an available patch at the time of disclosure increases the urgency for mitigation. Organizations relying on Shotcut for video editing workflows should be aware of this risk and prepare to apply fixes promptly once released.

For European organizations, the impact of CVE-2025-65834 is significant, particularly for those in media production, broadcasting, and creative industries that utilize Shotcut for video editing. Exploitation can lead to arbitrary code execution, allowing attackers to gain full control over affected systems, steal sensitive data, alter or destroy project files, and disrupt business operations. The vulnerability threatens confidentiality by exposing potentially sensitive media content and intellectual property. Integrity is compromised through unauthorized modification of video projects or system files. Availability is at risk due to potential crashes or denial of service caused by memory corruption. Given the remote, unauthenticated exploit vector, attackers can target vulnerable systems over networks without user interaction, increasing the attack surface. The absence of known exploits currently provides a window for proactive defense, but the critical severity demands immediate attention to prevent future attacks. Organizations with distributed teams or remote workflows using Shotcut are particularly vulnerable to supply chain or spear-phishing attacks delivering malicious project files.

1. Immediately restrict the opening of untrusted or unsolicited MLT project files in Shotcut environments until a patch is available. 2. Implement network-level controls such as email filtering and endpoint protection to detect and block malicious project files containing manipulated width and height parameters. 3. Monitor for anomalous application behavior or crashes related to Shotcut usage that could indicate exploitation attempts. 4. Engage with Meltytech or the open-source community to obtain and apply security patches as soon as they are released. 5. Consider sandboxing Shotcut processes or running them with least privilege to limit potential damage from exploitation. 6. Educate users on the risks of opening project files from unknown sources and enforce strict file handling policies. 7. Use application whitelisting and integrity monitoring to detect unauthorized modifications to Shotcut binaries or project files. 8. Maintain up-to-date backups of critical media projects to enable recovery in case of compromise. 9. Collaborate with cybersecurity teams to integrate this vulnerability into threat hunting and incident response playbooks.