CVE-2026-48095
HighCVSS 8.8Summary
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.
Risk Assessment
This vulnerability could lead to remote code execution, posing a serious security threat to systems using 7-Zip. If exploited, the organization may experience data loss or application downtime.
Recommendation
It is recommended to upgrade to version 26.01 or later to mitigate this vulnerability. Additionally, consider restricting access to the NTFS handling features in 7-Zip if not necessary.
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-2026-48104Medium
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.
- 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 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. ReadStream_FALSE 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.