CVE-2026-48101
GHSL-2026-117: 7-Zip UEFI Capsule uninitialized heap memory disclosure
CVSS Score
6.5
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-908 |
| Vendor | mcmilk |
| Product | 7-zip |
| Published | Jun 5, 2026 |
| Last Updated | Jun 5, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None
Affected Versions
mcmilk / 7-Zip
>= 9.21, < 26.01