CVE-2026-57243 in PDF Editor
Summary
by MITRE • 07/08/2026
During the process of page opening and form formatting, a JavaScript reentrancy results in an inconsistent document status. Subsequently, with outdated page information, the application attempts to access invalid addresses, causing the application to crash.
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Analysis
by VulDB Data Team • 07/08/2026
This vulnerability represents a complex JavaScript reentrancy issue that fundamentally undermines application stability and can potentially lead to more severe security consequences. The flaw manifests during the page opening and form formatting processes when JavaScript code executes in a manner that allows reentrant calls to occur while the document object is in an inconsistent state. This reentrancy condition creates a race scenario where multiple execution paths attempt to modify or access the same document resources simultaneously, leading to unpredictable behavior and potential memory corruption issues.
The technical implementation of this vulnerability involves the application's failure to properly manage the execution context during asynchronous operations within the JavaScript runtime environment. When form formatting occurs, the system should maintain a consistent document state throughout the processing cycle, but instead allows for reentrant calls that can modify the DOM structure while other operations are still in progress. This creates a scenario where subsequent code attempts to access elements or properties that may have been removed, altered, or invalidated by the reentrant execution path.
The operational impact of this vulnerability extends beyond simple application crashes to potentially enable more sophisticated attack vectors. When the application attempts to access invalid addresses due to the inconsistent document status, it can result in memory access violations that may be exploitable for code execution or information disclosure attacks. The crash behavior itself can also facilitate denial of service conditions, particularly in web applications where persistent availability is critical for business operations.
This vulnerability aligns with CWE-367, which specifically addresses Time-of-Check to Time-of-Use (TOCTOU) flaws and related reentrancy issues in software systems. The inconsistency in document status during page rendering creates a temporal gap between when the application checks the document state and when it operates on that state, allowing for malicious actors to manipulate the environment between these operations. The flaw also relates to ATT&CK technique T1203, which covers exploitation of input validation flaws and memory corruption vulnerabilities.
Mitigation strategies should focus on implementing proper synchronization mechanisms within JavaScript execution contexts to prevent reentrant calls during critical document processing operations. Developers must ensure that form formatting and page rendering processes maintain exclusive access to document resources throughout their execution cycles. Input validation and state checking should be implemented at multiple levels to detect and prevent access to invalid document addresses. Additionally, implementing proper error handling and graceful degradation mechanisms can help prevent complete application crashes while maintaining system stability.
The recommended approach involves restructuring the JavaScript code to eliminate reentrant scenarios through proper locking mechanisms or by ensuring that all document modifications occur in atomic operations. Memory management practices should be reviewed to ensure that objects accessed during form formatting are not prematurely destroyed or modified by concurrent execution paths. Regular security testing and static analysis of JavaScript code should include specific checks for reentrancy conditions and inconsistent state handling during asynchronous processing operations.
Organizations should also consider implementing application-level protections such as sandboxing mechanisms, strict content security policies, and runtime monitoring to detect and prevent exploitation attempts targeting this vulnerability class. The implementation of proper defensive programming practices including input sanitization, output encoding, and comprehensive error handling can significantly reduce the risk of successful exploitation while maintaining application functionality and user experience standards.