CVE-2026-48102
LowCVSS 3.1Exploitation Probability (EPSS)
Low risk8th percentile — higher than 8% of all known CVEs
Summary
7-Zip versions 9.11 through 26.00 contain a heap out-of-bounds read vulnerability in the UDF file identifier descriptor parser. The issue occurs when processing UDF images, potentially leading to information disclosure and application crashes.
Risk Assessment
Organizations may be exposed to sensitive information disclosure and system crashes, impacting service availability.
Recommendation
It is recommended to update 7-Zip to version 26.01 or later to mitigate this vulnerability.
Original NVD description (English source)
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.