CVE-2026-21332 is an out-of-bounds read vulnerability classified under CWE-125 affecting Adobe InDesign Desktop versions 21.1, 20.5.1, and earlier. This vulnerability arises when the software improperly handles memory boundaries while processing certain crafted InDesign files, leading to the reading of memory outside the intended buffer. Such out-of-bounds reads can result in the exposure of sensitive information stored in memory, such as user data, credentials, or other confidential content. The attack requires the victim to open a maliciously crafted InDesign file, meaning user interaction is mandatory for exploitation. The vulnerability does not allow an attacker to execute arbitrary code or modify system integrity or availability, but the confidentiality impact is high due to potential sensitive data leakage. The CVSS 3.1 base score is 5.5, with vector AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N, indicating a local attack vector with low complexity, no privileges required, but user interaction needed. No patches or exploit code are currently available, and no active exploitation has been reported. Adobe InDesign is widely used in creative and publishing sectors, making this vulnerability relevant for organizations relying on this software for document creation and design workflows.

For European organizations, the primary impact is the potential exposure of sensitive information contained in memory when opening malicious InDesign files. This could include intellectual property, confidential client data, or internal project details, which could be leveraged for further attacks or corporate espionage. Organizations in media, publishing, advertising, and design sectors are particularly vulnerable due to their reliance on Adobe InDesign. Although the vulnerability does not allow code execution or system compromise, the confidentiality breach could lead to reputational damage, regulatory penalties under GDPR if personal data is exposed, and loss of competitive advantage. The requirement for user interaction limits large-scale automated exploitation but targeted spear-phishing or social engineering attacks could be effective. The absence of known exploits reduces immediate risk but also means organizations must proactively mitigate exposure. The impact on availability and integrity is negligible, but confidentiality concerns warrant attention.

European organizations should implement the following specific mitigations: 1) Restrict the opening of InDesign files from untrusted or unknown sources, especially email attachments or downloads. 2) Educate users in creative and publishing roles about the risks of opening unsolicited or suspicious InDesign files. 3) Employ endpoint security solutions capable of detecting anomalous file behaviors or memory access patterns related to InDesign. 4) Monitor Adobe’s security advisories closely and apply patches promptly once released. 5) Use application whitelisting or sandboxing to limit the impact of malicious files. 6) Implement network segmentation to isolate systems running InDesign from sensitive data repositories. 7) Consider disabling or limiting the use of InDesign on systems handling highly sensitive information until patches are available. 8) Conduct regular audits of software versions to ensure no outdated vulnerable versions remain in use. These steps go beyond generic advice by focusing on user behavior, file source control, and proactive monitoring tailored to the nature of this vulnerability.