Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
AV AC PR UI S C I A CVSS EPSS %ile KEV N L N R U L N H 7.1 .0022 13.5 —
AFFECTED Product Versions Fixed 7-Zip >= 9.34, < 26.01 – —
TIMELINE May 20 Reserved by GitHub_M Jun 5 EXPLOIT PUBLISHED — CVE-2026-48103 (mcmilk 7-Zip). Public exploit reference added. Jun 5 Published (CNA: GitHub_M)
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.
| Date | Event | Detail |
|---|---|---|
| May 20, 2026 | Reserved | Reserved by GitHub_M |
| June 5, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-48103 (mcmilk 7-Zip). Public exploit reference added. |
| June 5, 2026 | Published | Published (CNA: GitHub_M) |
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|---|---|---|---|
| mcmilk | 7-Zip | — | >= 9.34, < 26.01 | — |
Authoritative record: CVE-2026-48103 at cve.org
Vendors: mcmilk
Weaknesses: CWE-125
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-48103 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.