Bug 2485508 (CVE-2026-48103) - CVE-2026-48103 7-Zip: off-by-one heap-based buffer over-read in the WIM archive handler
Summary: CVE-2026-48103 7-Zip: off-by-one heap-based buffer over-read in the WIM archi...
Keywords:
Status: NEW
Alias: CVE-2026-48103
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On: 2486334 2486335 2486336 2486337
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-06-05 17:01 UTC by OSIDB Bzimport
Modified: 2026-06-08 13:31 UTC (History)
0 users

Fixed In Version:
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Description OSIDB Bzimport 2026-06-05 17:01:41 UTC
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.


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