The vulnerability identified as CVE-2026-21491 is a heap-based buffer overflow in the InternationalColorConsortium's iccDEV library, specifically within the CIccTagTextDescription component responsible for handling Unicode text in ICC color profiles. ICC profiles are widely used for color management across various digital imaging and printing workflows. The flaw exists in versions of iccDEV prior to 2.3.1.2 and arises when processing malformed or maliciously crafted ICC profiles that cause the Unicode buffer to overflow the allocated heap memory. This overflow can lead to memory corruption, resulting in application crashes or potentially exploitable conditions. The CVSS 3.1 score of 6.1 indicates a medium severity, with the vector showing that the attack requires local access (AV:L), low complexity (AC:L), no privileges (PR:N), and user interaction (UI:R). The impact primarily affects availability (A:H) with limited confidentiality loss (C:L) and no integrity impact (I:N). No known exploits have been reported in the wild, and no workarounds exist aside from applying the patch introduced in version 2.3.1.2. The vulnerability is categorized under CWE-122 (Heap-based Buffer Overflow), CWE-125 (Out-of-bounds Read), and CWE-193 (Off-by-one Error), indicating memory safety issues. This vulnerability is relevant for any software or systems that incorporate iccDEV for ICC profile processing, including image editing, printing, and color management tools.

For European organizations, the primary impact of CVE-2026-21491 is the potential disruption of services that rely on ICC profile processing, such as digital printing, graphic design, photo editing, and publishing workflows. A successful exploit could cause application crashes leading to denial of service conditions, interrupting business operations and potentially causing delays in production or delivery of media content. Although the confidentiality impact is low, the availability impact is significant, especially for organizations with automated color management pipelines. This could affect print shops, media companies, and manufacturers using color calibration extensively. Additionally, if exploited in multi-user environments, it could be leveraged to cause broader service disruptions. Since exploitation requires local access and user interaction, the threat is somewhat limited to insider threats or scenarios where users open malicious ICC profiles, such as through phishing or compromised files. The lack of known exploits reduces immediate risk but does not eliminate the need for proactive mitigation.

1. Apply the official patch by upgrading iccDEV to version 2.3.1.2 or later as soon as possible to eliminate the vulnerability. 2. Implement strict validation and sanitization of ICC profiles before processing them, especially those received from untrusted or external sources. 3. Restrict local user permissions to limit the ability to execute or process untrusted ICC profiles, reducing the risk of exploitation. 4. Educate users about the risks of opening files from unknown or suspicious sources, particularly those containing ICC profiles embedded in images or documents. 5. Employ application whitelisting and sandboxing for software that processes ICC profiles to contain potential crashes and prevent escalation. 6. Monitor logs and system behavior for signs of crashes or abnormal activity related to ICC profile processing. 7. For organizations with automated workflows, implement integrity checks on ICC profiles and consider isolating processing environments to minimize impact.