CVE-2026-1991 identifies a null pointer dereference vulnerability in the libuvc library, specifically in the uvc_scan_streaming function located in src/device.c within the UVC Descriptor Handler component. Libuvc is an open-source library used for USB video device handling, commonly integrated into multimedia applications and embedded systems. The flaw arises when the function improperly handles certain inputs or states, leading to dereferencing a null pointer, which causes the affected process to crash. This vulnerability requires local access with low privileges (AV:L, PR:L) and does not require user interaction or authentication. The attack complexity is low, meaning an attacker with local access can reliably trigger the crash, resulting in denial of service. The CVSS 4.0 base score is 4.8, reflecting a medium severity level due to the limited attack vector and impact scope. No patches or fixes have been released yet, and the project maintainers have not responded to the initial report. While no known exploits are currently observed in the wild, the public availability of the exploit code increases the risk of future attacks. Systems using libuvc versions 0.0.1 through 0.0.7 are vulnerable, and any software or devices relying on this library for USB video streaming could be affected. The vulnerability primarily impacts availability by causing crashes but does not affect confidentiality or integrity.

For European organizations, the primary impact of CVE-2026-1991 is potential denial of service in systems utilizing libuvc for USB video device management. This could disrupt multimedia applications, video conferencing tools, or embedded systems relying on USB video streaming, leading to operational downtime or degraded service quality. Organizations in sectors such as telecommunications, media production, healthcare (medical imaging devices), and manufacturing (machine vision systems) could be particularly affected. The requirement for local access limits remote exploitation, but insider threats or compromised internal systems could leverage this vulnerability to cause disruptions. The absence of patches increases exposure time, and the public exploit availability raises the risk of opportunistic attacks. While the vulnerability does not compromise data confidentiality or integrity, service interruptions could impact business continuity and user experience. European entities with strict uptime and availability requirements may face reputational and financial consequences if affected systems crash unexpectedly.

To mitigate CVE-2026-1991, European organizations should first restrict local access to systems running vulnerable libuvc versions, enforcing strict access controls and monitoring for unauthorized local activity. Implement application whitelisting and endpoint protection to detect abnormal process crashes related to libuvc. Where possible, isolate devices using libuvc in segmented network zones to limit the impact of potential denial of service. Monitor system logs and crash reports to identify attempts to exploit the vulnerability. Engage with software vendors or open-source maintainers to obtain patches or updates as soon as they become available and plan for timely deployment. Consider recompiling libuvc with additional debugging or safety checks if feasible. For critical systems, evaluate alternative libraries or solutions that do not exhibit this vulnerability. Educate internal staff about the risks of local exploitation and enforce policies to minimize insider threats. Finally, maintain an incident response plan to quickly address any service disruptions caused by this vulnerability.