CVE-2026-21355 is a medium-severity vulnerability classified as an out-of-bounds read (CWE-125) in Adobe's Digital Negative (DNG) Software Development Kit (SDK), versions 1.7.1 2410 and earlier. The vulnerability arises when the SDK processes specially crafted DNG files, leading to reading memory beyond the intended buffer boundaries. This out-of-bounds read can result in the disclosure of sensitive information stored in adjacent memory areas, potentially leaking confidential data. The flaw does not allow code execution or modification of data but compromises confidentiality. Exploitation requires user interaction, specifically the victim opening a maliciously crafted DNG file, which could be delivered via email, file sharing, or other vectors. The vulnerability does not require any privileges or authentication, making it accessible to remote attackers who can trick users into opening malicious files. The CVSS 3.1 base score is 5.5, reflecting a medium severity with a high confidentiality impact but no integrity or availability impact. There are no known exploits in the wild at this time, and Adobe has not yet published patches or mitigation guidance. The DNG SDK is widely used in digital imaging applications and workflows, including professional photography and media production tools, which may incorporate this SDK for handling DNG files.

For European organizations, the primary impact of CVE-2026-21355 is the potential leakage of sensitive information from memory when processing malicious DNG files. This could expose confidential data such as cryptographic keys, personal information, or proprietary content if such data resides in memory near the vulnerable buffer. Organizations involved in media production, digital asset management, or photography that utilize software built on the Adobe DNG SDK are at risk. While the vulnerability does not allow code execution or system compromise, the confidentiality breach could lead to data privacy violations, intellectual property exposure, or compliance issues under regulations like GDPR. The requirement for user interaction limits large-scale automated exploitation but targeted spear-phishing or social engineering attacks remain plausible. The absence of known exploits reduces immediate risk, but the widespread use of the SDK in creative industries across Europe means the threat should be taken seriously.

Until official patches are released by Adobe, European organizations should implement several practical mitigations: 1) Educate users, especially those in creative and media departments, about the risks of opening unsolicited or suspicious DNG files from untrusted sources. 2) Employ email and endpoint security solutions that scan and block malicious or malformed DNG files. 3) Restrict the use of DNG files to trusted workflows and sources, and consider disabling automatic preview or processing of DNG files in applications where feasible. 4) Monitor for unusual application behavior or memory access patterns when handling DNG files. 5) Once Adobe releases patches, prioritize timely deployment across all affected systems. 6) Use application whitelisting and sandboxing to limit the impact of any malicious file processing. 7) Maintain updated backups and incident response plans to quickly address any potential data exposure incidents.