CVE-2026-48104
MediumCVSS 4.2Summary
7-Zip versions 9.18 through 26.00 contain a vulnerability in the SquashFS archive handler, involving an uninitialized heap read. This issue occurs when processing images with few inodes, potentially leading to memory information disclosure.
Risk Assessment
Organizations may be exposed to attacks that could lead to memory information disclosure and denial of service due to wild-pointer dereference. Version 26.01 addresses this vulnerability.
Recommendation
It is recommended to upgrade to version 26.01 or later to mitigate this vulnerability. Additionally, monitor the use of SquashFS archives in applications utilizing 7-Zip.
Other vulnerabilities in 7-Zip
See all- CVE-2026-48112Medium
7-Zip versions 9.18 through 26.00 contain a heap out-of-bounds read vulnerability in the BSD SYMDEF parser. The ParseLibSymbols function reads data beyond the allocated memory area, potentially leading to leakage of uninitialized data.
- CVE-2026-48095High
7-Zip versions 26.00 and prior contain a heap buffer overflow vulnerability caused by an under-allocation in the NTFS compressed stream buffer. Attackers may exploit this vulnerability to execute arbitrary code or cause application crashes.
- CVE-2026-48092Medium
7-Zip is a file archiver with a high compression ratio. Versions 9.34 through 26.00 contain a heap memory disclosure due to an integer overflow in the SquashFS ReadBlock function on 32-bit builds.
- CVE-2025-53816High
7-Zip is a file archiver with a high compression ratio. Versions of 7-Zip prior to 25.0.0 have an issue with writing zeroes outside the heap buffer in the RAR5 handler, which may lead to memory corruption and denial of service.
- CVE-2026-14266High
In 7-Zip, a heap-based buffer overflow vulnerability exists in XZ decompression that allows remote code execution. User interaction is required – the victim must visit a malicious page or open a malicious file. Crafted XZ-compressed data can trigger a heap-based buffer overflow.
- CVE-2026-58052Low
7-Zip for Windows up to version 26.01 fails to preserve the Mark-of-the-Web when extracting a crafted RAR5 archive. Its guard that suppresses an archive-supplied Zone.Identifier stream matches the exact name 'Zone.Identifier' while a RAR5 STM record named ':Zone.Identifier:$DATA' is not matched and NTFS canonicalizes it to the same stream, overwriting the propagated Internet-zone marker with ZoneId=0. A second STM record named '::$DATA' overwrites the extracted file's default data stream, letting an attacker defeat SmartScreen/MotW warnings and spoof file content.
- CVE-2026-48101Medium
7-Zip, a file archiver, contains an uninitialized memory disclosure vulnerability in the UEFI capsule (.scap) parser in versions 9.21 through 26.00. The OpenCapsule function allocates a heap buffer without zero-initialization, which may lead to unauthorized data exposure.
Original NVD description (English source)
7-Zip is a file archiver with a high compression ratio. Versions 9.18 through 26.00 contain an uninitialized heap read in the SquashFS archive handler caused by a sparsely populated index array. In the SquashFS handler, _blockToNode is allocated with capacity for every metadata block but populated only when an inode crosses a block boundary, so a crafted image with few inodes spanning many blocks leaves most slots holding raw heap contents (the underlying allocator does not zero-initialize POD storage). When OpenDir looks up an attacker-influenced blockIndex (derived from the RootInode superblock field), it reads two of these uninitialized slots and passes them as the left/right bounds of a binary search over _nodesPos, which dereferences the midpoint without bounds checking; if the resulting value happens to match the search key, the returned index is used to read a full node struct from _nodes whose fields feed further directory parsing, forming a chained OOB read primitive that is heap-layout-dependent and not reliably triggerable. The SquashFS handler is enabled by default in stock 7z.dll and the issue triggers during Open() with no interaction beyond opening the file; impact is denial of service from wild-pointer dereference and potential heap information disclosure, with no write primitive. Version 26.01 fixes the issue.