CVE-2026-21281 is a heap-based buffer overflow vulnerability (CWE-122) identified in Adobe InCopy, a professional word processing software widely used in publishing and media industries. The flaw exists in versions 21.0, 19.5.5, and earlier, allowing an attacker to craft a malicious InCopy file that, when opened by a user, triggers a buffer overflow in the heap memory. This overflow can corrupt memory structures, enabling arbitrary code execution within the context of the current user. The vulnerability requires user interaction, as the victim must open the malicious file, which limits remote exploitation but still poses a significant risk through phishing or malicious document distribution. The CVSS v3.1 score of 7.8 reflects high impact on confidentiality, integrity, and availability, with low attack complexity and no privileges required prior to exploitation. Although no exploits are currently known in the wild, the potential for attackers to leverage this vulnerability for code execution and lateral movement in corporate environments is substantial. The absence of published patches at the time of disclosure necessitates immediate risk mitigation and monitoring for updates from Adobe.

For European organizations, especially those in media, publishing, advertising, and creative sectors that rely heavily on Adobe InCopy, this vulnerability poses a significant threat. Successful exploitation can lead to arbitrary code execution, enabling attackers to steal sensitive intellectual property, manipulate documents, deploy malware, or move laterally within networks. The impact extends to confidentiality breaches, data integrity compromises, and potential denial of service if system stability is affected. Given the user interaction requirement, phishing campaigns or malicious file sharing are likely attack vectors. Organizations with large creative teams or distributed workforces are at higher risk. Additionally, the vulnerability could be leveraged in targeted attacks against high-profile media outlets or government-related publishing entities in Europe, potentially affecting information dissemination and trust.

1. Monitor Adobe’s official channels for patches and apply them immediately upon release. 2. Until patches are available, restrict the use of Adobe InCopy to trusted files and sources only. 3. Implement strict email filtering and user awareness training to reduce the risk of opening malicious files. 4. Employ application whitelisting and sandboxing techniques to limit the execution scope of InCopy processes. 5. Use endpoint detection and response (EDR) solutions to monitor for anomalous behavior indicative of exploitation attempts. 6. Regularly back up critical data and ensure recovery procedures are tested. 7. Consider network segmentation to isolate creative departments from sensitive or critical infrastructure. 8. Enforce the principle of least privilege to limit the impact of any successful exploitation.