CVE-2026-26282 in NanaZip
Summary
by MITRE • 02/19/2026
NanaZip is an open source file archive Starting in version 5.0.1252.0 and prior to version 6.0.1630.0, NanaZip has an out-of-bounds heap read in `.NET Single File` bundle header parser due to missing bounds check. Opening a crafted file with NanaZip causes a crash or leaks heap data to the user. Version 6.0.1630.0 patches the issue.
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Analysis
by VulDB Data Team • 02/22/2026
The vulnerability identified as CVE-2026-26282 affects NanaZip, an open source file archiving application that has been widely adopted for its efficient handling of compressed files. This security flaw exists within the application's parsing logic for .NET Single File bundle headers, specifically in versions between 5.0.1252.0 and 6.0.1630.0. The issue manifests as an out-of-bounds heap read condition that occurs when processing specially crafted archive files, representing a critical security concern for users who handle untrusted file content. The vulnerability stems from insufficient bounds checking during the parsing of bundle header structures, which allows attackers to manipulate the application's memory access patterns.
The technical implementation of this vulnerability resides in the .NET Single File bundle header parser component of NanaZip, where the application fails to validate the size and structure of incoming data before attempting to read from heap memory. When a maliciously constructed file is opened, the parser attempts to access memory locations beyond the allocated buffer boundaries, resulting in either an application crash or unintended information disclosure from heap memory regions. This type of vulnerability falls under the Common Weakness Enumeration category CWE-129, which addresses insufficient bounds checking in software implementations. The flaw represents a classic heap-based buffer overflow scenario where the application's memory management fails to enforce proper data boundaries during parsing operations.
The operational impact of this vulnerability extends beyond simple application instability, as it creates potential for information disclosure attacks that could expose sensitive heap data to attackers. When exploited, the vulnerability can cause denial of service through application crashes or potentially enable more sophisticated attacks depending on the memory layout and contents. The attack vector requires the victim to open a specifically crafted archive file with NanaZip, making it a user-initiated attack that relies on social engineering or trust-based file delivery methods. This vulnerability affects the core functionality of file archive handling and could potentially compromise user data integrity, particularly in environments where users frequently process files from untrusted sources or third-party providers.
Mitigation strategies for CVE-2026-26282 center around updating to the patched version 6.0.1630.0 or later, which implements proper bounds checking in the bundle header parser. System administrators and users should prioritize immediate deployment of the security update to protect against exploitation attempts. Additionally, organizations should implement defensive measures such as restricting file type execution permissions, employing sandboxed environments for archive processing, and maintaining updated antivirus signatures that can detect malicious archive files. The vulnerability aligns with ATT&CK technique T1059.007, which involves the use of application execution flaws to gain unauthorized access or execute malicious code, and represents a significant concern for enterprise security posture where file archive handling is a common operational activity. Regular security assessments of file processing applications and implementation of proper input validation controls can help prevent similar vulnerabilities from emerging in other software components.