CVE-2026-48101

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

Published Jun 5, 2026 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4681-1 p7zip security update
History
Type Values Removed Values Added
First Time appeared 7-zip
7-zip 7-zip
CPEs cpe:2.3:a:7-zip:7-zip:*:*:*:*:*:*:*:*
Vendors & Products 7-zip
7-zip 7-zip
Type Values Removed Values Added
First Time appeared Mcmilk
Mcmilk 7-zip
Vendors & Products Mcmilk
Mcmilk 7-zip
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title GHSL-2026-117: 7-Zip UEFI Capsule uninitialized heap memory disclosure
Weaknesses CWE-908
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jun 5, 2026, 7:38 PM
Reserved
May 20, 2026, 6:40 PM
Status
Analyzed
Published
Jun 5, 2026, 4:16 PM
Modified
Jun 17, 2026, 10:54 AM