CVE-2026-48103
A public proof of concept exists; no exploitation attested.
- Published2026-06-05
- Fixed in26.01
- WeaknessCWE-125
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
Description
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.
Timeline
dates in UTC- 2026-06-0517:16CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-25 15:37 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-48103?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-48103?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 26.1 | ≥ 9.34, < 26.01 | 26.01 | NVD |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Fix
- Update 7-zip to 26.01
Advisories and patches
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H
- Published
- 2026-06-05
- Last Modified
- 2026-06-17
- NVD status
- Analyzed
Frequently asked questions
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