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Fencer Vulns
medium 4.3

CVE-2026-48103 json

GHSL-2026-119 7-Zip WIM SecurityId OOB read

published 2026-06-05 5 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-34852

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.2%
EPSS 2.2% chance of exploitation in 30 days, percentile 82%
public exploits
0
none known

Summary

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.

Patch / fix

  • 7-zip 7-zip 26.01
  • 7zip Debian 12 22.01+really26.01+dfsg-0+deb12u1
  • 7zip Debian 14 26.01+dfsg-1
  • p7zip Debian 12 16.02+really26.01+dfsg-0+deb12u1
  • p7zip Debian 13 16.02+transitional.1

debian advisories DEBIAN-CVE-2026-48103

  • 7zip SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +8 more 26.01-150400.9.6.1
  • 7zip SLES for SAP applications 16.0, SLES 16.0 26.01-160000.1.1

suse advisories SUSE-SU-2026:2696-1SUSE-SU-2026:22347-1

  • 7zip openSUSE Tumbleweed 26.02-2.1
  • 7zip openSUSE Leap 16.0 26.01-160000.1.1

opensuse advisories openSUSE-SU-2026:11502-1openSUSE-SU-2026:21038-1

  • 7zip Alpine 3.24 26.01-r0

alpine advisories ALPINE-CVE-2026-48103

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-48103 updated cvss 6.1

7-Zip: off-by-one heap-based buffer over-read in the WIM archive handler

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

2.16% chance of exploitation in the next 30 days, higher than 82% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • securitylab.github.com https://securitylab.github.com/advisories/GHSL-2026-115_GHSL-2026-122_7-zip/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
NVD 3.1 7.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H

Affected products

  • mcmilk 7-Zip

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.