PT-2026-46970 · Mcmilk · 7-Zip

Published 2026-06-05 · Updated 2026-06-05 · CVE-2026-48101

NVD

CVSS v3.1

6.5

Medium

Base vector

AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

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.

Fix

Use of Uninitialized Resource

Weakness Enumeration

CWE-908

Related Identifiers

CVE-2026-48101

Affected Products

7-Zip

References · 2

• https://nvd.nist.gov/vuln/detail/CVE-2026-48101 · Security Note
• https://securitylab.github.com/advisories/GHSL-2026-115_GHSL-2026-122_7-zip · Note