Threat Intelligence Database

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 SECTION_DXE_DEPEX (0x13) or SECTION_PEI_DEPEX (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.

7-Zip is a file archiver with a high compression ratio. Versions 9.11 through 26.00 contain a heap out-of-bounds read of up to 3 bytes in the UDF disc image handler's File Identifier Descriptor parser. In CFileId::Parse (CPP/7zip/Archive/Udf/UdfIn.cpp), after validating size < 38 + idLen + impLen and advancing processed to 38 + impLen + idLen, the alignment-padding loop reads p[processed] while incrementing up to 3 times to reach a 4-byte boundary, and the processed <= size bounds check only runs after the loop. When (38 + impLen + idLen) % 4 != 0 and 38 + impLen + idLen == size, the loop reads 1 to 3 bytes past the end of the exact-size heap buffer allocated via buf.Alloc((size_t)item.Size). The UDF handler is registered for .iso and .udf files and auto-detected by signature, and the OOB read triggers during Open() when listing or extracting a crafted UDF image. Impact is limited to information disclosure (a 1-bit oracle per OOB byte via open/fail behavior) and denial of service (crash under hardened allocators); there is no write primitive. Version 26.01 fixes the issue.

A heap buffer overflow vulnerability exists in 7-Zip versions 26.00 and earlier due to an under-allocation in the NTFS compressed stream buffer. This flaw can lead to arbitrary code execution or application crashes when processing specially crafted NTFS images. The vulnerability arises from an undefined behavior in buffer size calculation that results in a 1-byte allocation overwritten by up to 256 MB of data. The issue is fixed in version 26.01.

A heap memory disclosure vulnerability exists in 32-bit builds of 7-Zip versions 9.34 through 26.00 due to an integer overflow in the SquashFS ReadBlock function. This overflow allows an attacker-controlled offset to bypass fragment bounds checks, causing memcpy to read memory preceding the cache buffer into the extracted file. The issue is fixed in version 26.01. The vulnerability has a medium severity rating with a CVSS score of 4.3.

7-Zip is a file archiver with a high compression ratio.7-Zip supports extracting from Compound Documents. Prior to version 25.0.0, a null pointer dereference in the Compound handler may lead to denial of service. Version 25.0.0 contains a fix cor the issue.

MediumVulnerabilityGermanyFranceUnited Kingdom+5#cve#cve-2025-53817#cwe-476

7-Zip is a file archiver with a high compression ratio. Zeroes written outside heap buffer in RAR5 handler may lead to memory corruption and denial of service in versions of 7-Zip prior to 25.0.0. Version 25.0.0 contains a fix for the issue.

The NtfsHandler.cpp NTFS handler in 7-Zip before 24.01 (for 7zz) contains an out-of-bounds read that allows an attacker to read beyond the intended buffer. The bytes read beyond the intended buffer are presented as a part of a filename listed in the file system image. This has security relevance in some known web-service use cases where untrusted users can upload files and have them extracted by a server-side 7-Zip process.

HighVulnerabilityGermanyFranceUnited Kingdom+5#cve#cve-2023-52169