CVE-2025-59801 is a stack-based buffer overflow vulnerability identified in Artifex GhostXPS versions prior to 10.06.0. The flaw resides in the function xps_unpredict_tiff within the source file xpstiff.c. Specifically, the vulnerability arises because the 'samplesperpixel' value, which dictates the number of color samples per pixel in TIFF image processing, is not properly validated before being used. This lack of validation can lead to a buffer overflow on the stack, as the program may write more data than the allocated buffer can hold. The vulnerability is classified under CWE-121, indicating a classic stack-based buffer overflow. According to the CVSS v3.1 scoring, the vulnerability has a score of 4.3, categorized as medium severity. The vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N indicates that the attack requires local access (AV:L), has low attack complexity (AC:L), does not require privileges (PR:N), and no user interaction (UI:N). The scope is changed (S:C), meaning the vulnerability affects resources beyond the vulnerable component. The impact is limited to integrity (I:L) with no confidentiality or availability impact. No known exploits are currently reported in the wild, and no patches have been linked yet. This vulnerability could be exploited by an attacker with local access to the system to execute arbitrary code or cause memory corruption, potentially leading to integrity violations such as unauthorized modification of data or control flow within the GhostXPS processing pipeline. Given the nature of GhostXPS as a software handling XPS and TIFF files, exploitation might be triggered by processing crafted image files, possibly leading to local privilege escalation or code execution if combined with other vulnerabilities or misconfigurations.

For European organizations, the impact of CVE-2025-59801 depends largely on the deployment of Artifex GhostXPS within their environments. GhostXPS is used for processing XPS and TIFF documents, often in printing, document management, or imaging workflows. Organizations in sectors such as publishing, printing, government, and legal services that handle large volumes of such documents may be at risk. The vulnerability requires local access, which limits remote exploitation but raises concerns for insider threats or compromised internal systems. Successful exploitation could lead to integrity breaches, such as unauthorized modification of documents or processing results, potentially undermining document authenticity and trustworthiness. This could have regulatory implications under GDPR if document integrity is critical to compliance. Additionally, if attackers leverage this vulnerability as part of a multi-stage attack, it could facilitate lateral movement or privilege escalation within networks. The medium CVSS score reflects moderate risk, but the changed scope and integrity impact suggest that affected systems could be manipulated beyond the immediate vulnerable component, increasing potential damage in complex environments.

To mitigate CVE-2025-59801 effectively, European organizations should: 1) Monitor Artifex's official channels for patches or updates addressing this vulnerability and apply them promptly once available. 2) Implement strict access controls to limit local access to systems running GhostXPS, reducing the attack surface. 3) Employ application whitelisting and sandboxing techniques to isolate GhostXPS processes, preventing exploitation from affecting other system components. 4) Conduct regular code audits and fuzz testing on image processing components to detect similar vulnerabilities proactively. 5) Use network segmentation to separate document processing systems from critical infrastructure, minimizing lateral movement risks. 6) Educate internal users about the risks of opening or processing untrusted XPS or TIFF files, even locally. 7) Deploy endpoint detection and response (EDR) solutions capable of identifying anomalous behavior related to buffer overflow exploitation attempts. 8) Review and harden system configurations and privilege assignments to ensure minimal necessary permissions for GhostXPS operation. These targeted measures go beyond generic advice by focusing on the specific attack vector (local access and image processing) and the operational context of GhostXPS.