CVE-2026-3774 in PDF Editor
Summary
by MITRE • 04/01/2026
The application allows PDF JavaScript and document/print actions (such as WillPrint/DidPrint) to update form fields, annotations, or optional content groups (OCGs) immediately before or after redaction, encryption, or printing. These script‑driven updates are not fully covered by the existing redaction, encryption, and printing logic, which, under specific document structures and user workflows, may cause a small amount of sensitive content to remain unremoved or unencrypted as expected, or result in printed output that slightly differs from what was reviewed on screen.
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Analysis
by VulDB Data Team • 04/29/2026
This vulnerability resides in the handling of PDF document processing operations where JavaScript execution and document actions are permitted to modify content during critical processes such as redaction encryption and printing. The flaw manifests when document objects including form fields annotations and optional content groups can be altered through script execution immediately before or after these operations. The core technical issue stems from insufficient isolation between the script execution environment and the security-critical document modification processes. When redaction occurs, for example, a script might execute during the WillPrint or DidPrint events that could potentially restore or modify content that should have been removed. This represents a failure in access control and data integrity mechanisms that should prevent any unauthorized modifications during security-sensitive operations. The vulnerability aligns with CWE-693 Protection Mechanism Failure, specifically when security controls fail to properly isolate or validate operations during critical document processing phases.
The operational impact of this vulnerability extends beyond simple data leakage to encompass potential information disclosure and integrity compromise within document security workflows. Attackers could exploit this weakness by crafting malicious PDF documents containing JavaScript that executes during redaction or encryption processes, potentially leaving sensitive information accessible or altering the encrypted state of portions of documents. The vulnerability is particularly concerning in environments where documents contain classified information, personal data, or proprietary content where strict redaction and encryption requirements must be maintained. When printing operations occur, the discrepancy between screen review and actual printed output could lead to accidental disclosure of sensitive content that was not properly removed during the redaction process. This vulnerability can be categorized under ATT&CK technique T1059.007 for JavaScript execution and T1566 for credential access through document manipulation, depending on the specific attack vector employed.
Mitigation strategies must address the fundamental architectural flaw in how script execution interacts with security-critical document operations. Organizations should implement strict isolation of script execution environments from document modification processes during redaction and encryption operations, ensuring that no external script can alter document state during these critical phases. The recommended approach involves disabling JavaScript execution entirely during security-sensitive operations or implementing strict sandboxing mechanisms that prevent modification of redacted or encrypted content. Additionally, document validation should include verification that no unauthorized changes occurred during processing, with automated checks that compare pre and post-operation document states. Security controls should enforce that form fields annotations and OCGs cannot be modified during redaction or encryption workflows, with logging and alerting mechanisms to detect any unauthorized attempts to manipulate these elements. The implementation of these controls should align with security frameworks such as NIST SP 800-53 and ISO/IEC 27001 requirements for information security controls and access management.