CVE-2025-9809 is a high-severity vulnerability classified as CWE-787 (Out-of-bounds Write) found in the libretro-common library, specifically within the function cdfs_open_cue_track. This vulnerability arises when processing crafted .cue files containing file paths that exceed the defined PATH_MAX_LENGTH. The vulnerable code copies the file path into a fixed-size buffer using memcpy without adequate bounds checking, leading to an out-of-bounds write condition. This memory corruption flaw can be exploited by remote attackers to execute arbitrary code on affected systems. The vulnerability affects all platforms running the latest versions of libretro-common, which is a core library used by the libretro project to provide a common API for emulators and game engines. The CVSS 4.0 base score is 8.4, indicating high severity, with an attack vector of local (AV:L), low attack complexity (AC:L), no privileges required (PR:N), but requiring user interaction (UI:A). The vulnerability impacts confidentiality, integrity, and availability at a high level, with no scope change. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability was published on September 1, 2025, and assigned by CyberArk. Given the nature of the flaw, exploitation would typically require a user to open or load a maliciously crafted .cue file, which is common in emulation environments that use libretro-common for media and game disc image handling.

For European organizations, the impact of CVE-2025-9809 could be significant, especially for those involved in software development, digital preservation, gaming, and emulation services that utilize libretro-common. Successful exploitation could lead to arbitrary code execution, allowing attackers to gain control over affected systems, potentially leading to data breaches, system compromise, or disruption of services. Organizations relying on emulation for legacy software or digital media management may face increased risk. The requirement for user interaction means phishing or social engineering could be vectors for exploitation, increasing the risk in environments where users handle .cue files from untrusted sources. Confidentiality, integrity, and availability of systems could be severely impacted, potentially affecting sensitive data and operational continuity. Additionally, the lack of current patches may delay remediation, increasing exposure time.

To mitigate CVE-2025-9809, European organizations should: 1) Immediately audit their software stacks to identify any use of libretro-common, especially in applications handling .cue files or disc images. 2) Restrict or monitor the opening of .cue files from untrusted or external sources, implementing strict file validation and sandboxing where possible. 3) Employ application whitelisting and endpoint protection solutions capable of detecting anomalous behavior related to memory corruption exploits. 4) Educate users about the risks of opening files from untrusted sources, emphasizing caution with .cue files and similar media. 5) Monitor vendor communications closely for patches or updates addressing this vulnerability and prioritize timely deployment once available. 6) Consider implementing runtime memory protection techniques such as Address Space Layout Randomization (ASLR) and Data Execution Prevention (DEP) to reduce exploitability. 7) For developers using libretro-common, review and contribute to upstream fixes or implement custom bounds checking to prevent out-of-bounds writes.