Adobe InCopy Zero-Day: Arbitrary Code Execution Risk

The National Vulnerability Database (NVD) recently flagged CVE-2026-34631, a high-severity out-of-bounds write vulnerability impacting Adobe InCopy versions 20.5.2, 21.2, and earlier. This flaw could enable an attacker to achieve arbitrary code execution, running malicious code in the context of the current user. It’s a classic case of a memory corruption bug, specifically a CWE-787 out-of-bounds write, which often leads to critical impact.

Exploitation of this vulnerability isn’t entirely silent; it requires user interaction. A victim would need to open a specially crafted, malicious file. This social engineering component is a common vector for client-side exploits, often delivered via phishing campaigns or compromised websites. Despite the user interaction requirement, a CVSS score of 7.8 (HIGH) indicates the significant danger this vulnerability poses, especially given the widespread use of Adobe products in professional environments.