CVE-2026-34705: 
Adobe InDesign vulnerability analysis and mitigation

CVE-2026-34705 is an out-of-bounds read vulnerability (CWE-125) in Adobe InDesign Desktop that can lead to disclosure of sensitive process memory. It affects InDesign Desktop versions 21.3 and earlier (in the 21.x branch) and versions 20.5.3 and earlier (in the 20.x branch) on both Windows and macOS. Adobe disclosed and patched this vulnerability on June 9, 2026. It carries a CVSS v3.1 base score of 5.5 (Medium) (Adobe Advisory, GitHub Advisory).

The vulnerability is classified as CWE-125 (Out-of-bounds Read), meaning the application reads data beyond the intended buffer boundary when processing a specially crafted file. The attack vector is local, requiring no privileges, but does require user interaction — specifically, a victim must open a malicious InDesign file. When the file is parsed, the out-of-bounds read can expose contents of the InDesign process memory to the attacker, potentially revealing sensitive data such as credentials, keys, or other in-memory information. No public proof-of-concept or detailed technical write-up has been identified at this time (Adobe Advisory, GitHub Advisory).

Successful exploitation results in high confidentiality impact — an attacker can read sensitive data from the InDesign process memory — while integrity and availability are unaffected. The vulnerability is limited in scope to the local system where the malicious file is opened, with no scope change or privilege escalation implied. The primary risk is information disclosure, which could expose sensitive in-memory data such as cryptographic material or user credentials that might facilitate further attacks (Adobe Advisory, GitHub Advisory).

1. Craft a malicious InDesign file: An attacker creates a specially crafted Adobe InDesign document (.indd or similar format) that triggers an out-of-bounds read during file parsing.
2. Deliver the file to the victim: The attacker distributes the malicious file via phishing email, file-sharing platform, or other social engineering means, targeting users of vulnerable InDesign versions (21.3 or earlier, 20.5.3 or earlier).
3. Victim opens the file: The victim opens the malicious file in Adobe InDesign Desktop on Windows or macOS, triggering the vulnerable parsing code path.
4. Out-of-bounds read occurs: The application reads memory beyond the intended buffer, exposing sensitive process memory contents.
5. Memory disclosure: Depending on the implementation, the attacker may receive the leaked memory contents embedded in an error response, a crafted output file, or via a side-channel, potentially revealing sensitive data such as credentials or cryptographic keys (Adobe Advisory, GitHub Advisory).

Adobe has released patched versions addressing this vulnerability: users on the 21.x branch should update to InDesign Desktop 21.4 or later, and users on the 20.x branch should update to version 20.5.4 or later. As a general workaround, users should avoid opening InDesign files from untrusted or unknown sources. Organizations may also consider implementing application sandboxing or restricting InDesign's network access to limit the potential impact of exploitation (Adobe Advisory).