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Fencer Vulns
medium 6.5

CVE-2026-48101 json

GHSL-2026-117: 7-Zip UEFI Capsule uninitialized heap memory disclosure

published 2026-06-05 5 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-34849

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 20%
public exploits
0
none known

Summary

7-Zip is a file archiver with a high compression ratio. Versions 9.21 through 26.00 contain an An uninitialized memory disclosure vulnerability in the UEFI capsule (.scap) parser in 7-Zip. The OpenCapsule function allocates a heap buffer of attacker-declared CapsuleImageSize (up to 1 GiB) without zero-initialization, then reads the file contents into it with ReadStream_FALSE whose return value is silently discarded. If the file is truncated, the unread tail of the buffer retains uninitialized heap memory, which is then exposed as extracted file content via GetStream. Version 26.0.1 fixes the issue.

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-2026-48101

  • 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-2026-48101

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-2026-48101 updated cvss 6.5

7-Zip: 7-Zip: Information Disclosure via uninitialized memory in UEFI capsule parser

  • 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
none
Automatable
no
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

0.28% chance of exploitation in the next 30 days, higher than 20% 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 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Affected products

  • mcmilk 7-Zip

Classification

Weakness
  • CWE-908 Use of Uninitialized Resource

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.