Unspecified vulnerability in 7-zip before 4.5.7 has unknown impact and remote attack vectors, as demonstrated by the PROTOS GENOME test suite for Archive Formats (c10).

7-Zip is a file archiver with a high compression ratio. Versions 26.00 and prior contain a heap buffer overflow vulnerability caused by an under-allocation in the NTFS compressed stream buffer (GetCuSize shift UB), potentially allowing attackers to cause arbitrary code execution or application crashes. CInStream::GetCuSize() in the NTFS handler computes the compression-unit buffer size as (UInt32)1 << (BlockSizeLog + CompressionUnit), and a crafted image with ClusterSizeLog >= 28 and CompressionUnit == 4 drives the exponent to 32, which is undefined behavior and collapses on x86/x64 so inBuf is allocated as 1 byte. ReadStreamFALSE then writes up to 256 MB of attacker-controlled data into that 1-byte buffer in 64 KB iterations, and because the CInStream object sits only 304 bytes after inBuf, its vtable pointer is overwritten and the next dispatched call achieves a vtable hijack. On 32-bit builds the overflow is unconditionally reached; on 64-bit it requires the parallel 8 GB outBuf allocation to succeed, otherwise failing closed to denial of service. The NTFS handler is enabled by default in stock 7z.dll and, via signature-based fallback matching "NTFS " at offset 3, will open a crafted image regardless of file extension during extraction or testing. Version 26.01 fixes the issue.

Last updated 25 August 2025

7-Zip is a file archiver with a high compression ratio. Versions 9.34 through 26.00 contain a heap memory disclosure via SquashFS fragment offset integer overflow on 32-bit builds. 32-bit integer overflow in the SquashFS ReadBlock function allows an attacker-controlled node.Offset value to bypass the fragment bounds check, causing memcpy to read heap memory preceding the cache buffer into the extracted file. The vulnerability is exploitable only on 32-bit builds of 7-Zip where sizet is 32 bits, allowing the addition offsetInBlock + blockSize to wrap modulo 2³². On 64-bit builds the addition is promoted to 64 bits and the check correctly rejects the input. Version 26.01 patches the issue.

This vulnerability allows remote attackers to execute arbitrary code on affected installations of 7-Zip. Interaction with this library is required to exploit this vulnerability but attack vectors may vary depending on the implementation. The specific flaw exists within the implementation of Zstandard decompression. The issue results from the lack of proper validation of user-supplied data, which can result in an integer underflow before writing to memory. An attacker can leverage this vulnerability to execute code in the context of the current process.

This vulnerability allows remote attackers to execute arbitrary code on affected installations of 7-Zip. Interaction with this library is required to exploit this vulnerability but attack vectors may vary depending on the implementation. The specific flaw exists within the implementation of Zstandard decompression. The issue results from the lack of proper validation of user-supplied data, which can result in an integer underflow before writing to memory. An attacker can leverage this vulnerability to execute code in the context of the current process.

7-Zip Zstandard Decompression Integer Underflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of 7-Zip. Interaction with this library is required to exploit this vulnerability but attack vectors may vary depending on the implementation.

The specific flaw exists within the implementation of Zstandard decompression. The issue results from the lack of proper validation of user-supplied data, which can result in an integer underflow before writing to memory. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-24346.

7-Zip ZIP File Parsing Directory Traversal Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of 7-Zip. Interaction with this product is required to exploit this vulnerability but attack vectors may vary depending on the implementation.

The specific flaw exists within the handling of symbolic links in ZIP files. Crafted data in a ZIP file can cause the process to traverse to unintended directories. An attacker can leverage this vulnerability to execute code in the context of a service account. Was ZDI-CAN-26753.

7-Zip ZIP File Parsing Directory Traversal Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of 7-Zip. Interaction with this product is required to exploit this vulnerability but attack vectors may vary depending on the implementation.

The specific flaw exists within the handling of symbolic links in ZIP files. Crafted data in a ZIP file can cause the process to traverse to unintended directories. An attacker can leverage this vulnerability to execute code in the context of a service account. Was ZDI-CAN-26743.

7-Zip XZ Decompression Heap-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of 7-Zip. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.

The specific flaw exists within the processing of XZ chunked data. Crafted XZ-compressed data can trigger an overflow of a heap-based buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-30169.

Insufficient exception handling in the method NCompress::NRar3::CDecoder::Code of 7-Zip before 18.00 and p7zip can lead to multiple memory corruptions within the PPMd code, allows remote attackers to cause a denial of service (segmentation fault) or execute arbitrary code via a crafted RAR archive.

Heap-based buffer overflow in the NCompress::NShrink::CDecoder::CodeReal method in 7-Zip before 18.00 and p7zip allows remote attackers to cause a denial of service (out-of-bounds write) or potentially execute arbitrary code via a crafted ZIP archive.

Heap-based buffer overflow in the NArchive::NHfs::CHandler::ExtractZlibFile method in 7zip before 16.00 and p7zip allows remote attackers to execute arbitrary code via a crafted HFS+ image.

DISPUTED 7-Zip through 21.07 on Windows allows privilege escalation and command execution when a file with the .7z extension is dragged to the Help>Contents area. This is caused by misconfiguration of 7z.dll and a heap overflow. The command runs in a child process under the 7zFM.exe process. NOTE: multiple third parties have reported that no privilege escalation can occur.

7-Zip is a file archiver with a high compression ratio. Versions 9.34 through 26.00 contain an off-by-one heap out-of-bounds read in the WIM (Windows Imaging) archive handler's security descriptor lookup. In CHandler::GetSecurity (CPP/7zip/Archive/Wim/WimHandler.cpp), the per-image SecurOffsets table holds numEntries + 1 cumulative offsets, but the check securityId >= SecurOffsets.Size() admits securityId == numEntries, and the function then reads SecurOffsets[securityId + 1], fetching one UInt32 past the end of the heap-allocated CRecordVector (which performs no bounds checking on operator[]). The securityId is attacker-controlled at offset +0xC of any directory entry in WIM metadata, and the handler is registered for .wim, .swm, .esd, and .ppkg and enabled by default in stock 7z.dll; the OOB triggers zero-click in the GUI because 7zFM.exe's ListView calls GetRawProp(kpidNtSecure) for every item during listing (ASan-confirmed), and is also reachable via CLI listing with 7zz l -slt. Impact is limited to denial of service under hardened allocators and minor information disclosure, since the OOB value is only consumed arithmetically as a length and is not surfaced to the attacker; there is no write primitive.

7-Zip is a file archiver with a high compression ratio. Versions 9.21 through 26.00 contain an off-by-one out-of-bounds read vulnerability in the ParseDepedencyExpression function of the UEFI firmware image parser(CPP/7zip/Archive/UefiHandler.cpp). The function validates an attacker-controlled opcode byte using > instead of >= against the element count of the 10-entry kExpressionCommands static array, allowing an opcode value of 10 to read one pointer slot (8 bytes on x64) past the end of the array in .rodata. The out-of-bounds value is then dereferenced as a const char and passed through strlen and memcpy into the archive's Characts property, which may cause either a denial of service (access violation when the adjacent bytes do not form a valid readable pointer) or a minor information disclosure of an adjacent .rdata string literal into archive metadata. The vulnerability is reached automatically during IInArchive::Open() via the call path OpenFv/OpenCapsule → ParseVolume → ParseSections when processing a SECTIONDXEDEPEX (0x13) or SECTIONPEIDEPEX (0x1B) section whose first body byte is 0x0A, and the UEFI handler is enabled by default in stock 7z.dll with signature-based detection for both UEFIc and UEFIf formats. The outcome (crash vs. silent leak) is deterministic per build but linker-layout dependent, with no write primitive and no disclosure of heap data, secrets, or ASLR base addresses. Version 26.01 fixes the issue.

This vulnerability allows remote attackers to bypass the Mark-of-the-Web protection mechanism on affected installations of 7-Zip. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the handling of archived files. When extracting files from a crafted archive that bears the Mark-of-the-Web, 7-Zip does not propagate the Mark-of-the-Web to the extracted files. An attacker can leverage this vulnerability to execute arbitrary code in the context of the current user.

This vulnerability allows remote attackers to bypass the Mark-of-the-Web protection mechanism on affected installations of 7-Zip. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the handling of archived files. When extracting files from a crafted archive that bears the Mark-of-the-Web, 7-Zip does not propagate the Mark-of-the-Web to the extracted files. An attacker can leverage this vulnerability to execute arbitrary code in the context of the current user.

7-Zip contains a protection mechanism failure vulnerability that allows remote attackers to bypass the Mark-of-the-Web security feature to execute arbitrary code in the context of the current user.

This vulnerability allows remote attackers to execute arbitrary code on affected installations of 7-Zip. Interaction with this product is required to exploit this vulnerability but attack vectors may vary depending on the implementation. The specific flaw exists within the handling of symbolic links in ZIP files. Crafted data in a ZIP file can cause the process to traverse to unintended directories. An attacker can leverage this vulnerability to execute code in the context of a service account.

This vulnerability allows remote attackers to execute arbitrary code on affected installations of 7-Zip. Interaction with this product is required to exploit this vulnerability but attack vectors may vary depending on the implementation. The specific flaw exists within the handling of symbolic links in ZIP files. Crafted data in a ZIP file can cause the process to traverse to unintended directories. An attacker can leverage this vulnerability to execute code in the context of a service account.

This vulnerability allows remote attackers to execute arbitrary code on affected installations of 7-Zip. Interaction with this product is required to exploit this vulnerability but attack vectors may vary depending on the implementation. The specific flaw exists within the handling of symbolic links in ZIP files. Crafted data in a ZIP file can cause the process to traverse to unintended directories. An attacker can leverage this vulnerability to execute code in the context of a service account.

This vulnerability allows remote attackers to execute arbitrary code on affected installations of 7-Zip. Interaction with this product is required to exploit this vulnerability but attack vectors may vary depending on the implementation. The specific flaw exists within the handling of symbolic links in ZIP files. Crafted data in a ZIP file can cause the process to traverse to unintended directories. An attacker can leverage this vulnerability to execute code in the context of a service account.

This vulnerability allows remote attackers to execute arbitrary code on affected installations of 7-Zip. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the processing of XZ chunked data. Crafted XZ-compressed data can trigger an overflow of a heap-based buffer. An attacker can leverage this vulnerability to execute code in the context of the current process.

This vulnerability allows remote attackers to execute arbitrary code on affected installations of 7-Zip. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the processing of XZ chunked data. Crafted XZ-compressed data can trigger an overflow of a heap-based buffer. An attacker can leverage this vulnerability to execute code in the context of the current process.

7-Zip before 26.03 contains an uninitialized memory disclosure vulnerability in the SquashFS v4 archive handler (SquashfsHandler.cpp) that allows attackers to leak heap memory by crafting a malicious archive where the superblock’s noids field is set so that the final metadata block’s expected size is miscomputed and bypasses the size validation check. By listing or extracting the crafted archive, attackers can cause the application to return uninitialized heap memory as the kpidUserId and kpidGroupId properties, exposing potentially sensitive process memory contents to the user.

Stack consumption vulnerability in AkkyWareHOUSE 7-zip32.dll before 4.42.00.04, as derived from Igor Pavlov 7-Zip before 4.53 beta, allows user-assisted remote attackers to execute arbitrary code via a long filename in an archive, leading to a heap-based buffer overflow.

This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of 7-Zip. Interaction with this library is required to exploit this vulnerability but attack vectors may vary depending on the implementation. The specific flaw exists within the processing of streams. The issue results from a logic error that can lead to an infinite loop. An attacker can leverage this vulnerability to create a denial-of-service condition on the system.

This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of 7-Zip. Interaction with this library is required to exploit this vulnerability but attack vectors may vary depending on the implementation. The specific flaw exists within the processing of streams. The issue results from a logic error that can lead to an infinite loop. An attacker can leverage this vulnerability to create a denial-of-service condition on the system.

7-Zip CopyCoder Infinite Loop Denial-of-Service Vulnerability. This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of 7-Zip. Interaction with this library is required to exploit this vulnerability but attack vectors may vary depending on the implementation.

The specific flaw exists within the processing of streams. The issue results from a logic error that can lead to an infinite loop. An attacker can leverage this vulnerability to create a denial-of-service condition on the system. Was ZDI-CAN-24307.