CVE-2026-21275 is a vulnerability classified under CWE-824, which pertains to the access of uninitialized pointers within Adobe InDesign Desktop software. Affected versions include 21.0, 19.5.5, and earlier releases. The flaw allows an attacker to craft a malicious InDesign file that, when opened by a user, triggers the use of an uninitialized pointer leading to arbitrary code execution. This means the attacker can execute code with the privileges of the current user, potentially compromising confidentiality, integrity, and availability of the system. The vulnerability requires user interaction, specifically opening a malicious file, and does not require prior authentication or elevated privileges. The CVSS 3.1 base score is 7.8, reflecting a high severity due to the combination of local attack vector, low attack complexity, no privileges required, but requiring user interaction. No public exploits have been reported yet, but the risk remains significant given the widespread use of Adobe InDesign in professional environments. The vulnerability could be leveraged to deploy malware, steal sensitive data, or disrupt operations. Adobe has not yet published patches, so mitigation currently relies on user education and security controls.

For European organizations, the impact of CVE-2026-21275 is considerable, especially for those in sectors heavily reliant on Adobe InDesign, such as publishing, advertising, media production, and graphic design. Successful exploitation could lead to unauthorized code execution, enabling attackers to steal intellectual property, deploy ransomware, or move laterally within networks. Confidentiality is at risk due to potential data exfiltration, integrity could be compromised by unauthorized modifications, and availability might be affected if malware disrupts operations. The requirement for user interaction limits mass exploitation but targeted spear-phishing campaigns could be effective. Organizations with lax patch management or insufficient endpoint protection are particularly vulnerable. The absence of known exploits in the wild provides a window for proactive defense, but the high CVSS score underscores the need for urgent attention.

1. Monitor Adobe’s official channels for patches and apply updates immediately once available. 2. Implement strict file handling policies to restrict opening InDesign files from untrusted or unknown sources. 3. Educate users about the risks of opening unsolicited or suspicious files, emphasizing the need for caution with email attachments and downloads. 4. Deploy endpoint detection and response (EDR) solutions capable of identifying anomalous behavior related to code execution from user applications. 5. Use application whitelisting to limit execution of unauthorized code. 6. Employ network segmentation to contain potential breaches originating from compromised user systems. 7. Regularly back up critical data and verify backup integrity to mitigate ransomware risks. 8. Conduct simulated phishing exercises to raise awareness and test user readiness. 9. Review and tighten user privilege assignments to minimize the impact of compromised accounts. 10. Maintain up-to-date antivirus and antimalware solutions with heuristic and signature-based detection.